Chip capacitor and method for manufacturing the same

ABSTRACT

[Theme] To provide a chip capacitor capable of easily and rapidly accommodating a plurality of types of capacitance values using a common design and a method for manufacturing the chip capacitor. [Solution] A chip capacitor  1  includes a substrate  2 , a first external electrode  3 , a second external electrode  4 , capacitor elements C 1  to C 19 , and fuses F 1  to F 9  disposed on the substrate  2 . The capacitor elements C 1  to C 19  respectively include a first electrode film  11 , a first capacitance film  12  on the first electrode film  11 , a second electrode film  13  disposed on the first capacitance film  12  and facing the first electrode film  11 , a second capacitance film  17  on the second electrode film  13 , and a third electrode film  16  disposed on the second capacitance film  17  and facing the second electrode film  13  and are connected between the first external electrode  3  and the second external electrode  4 . The fuses F 1  to F 9  are each interposed between the capacitor elements C 1  to C 19  and the first external electrode  3  or the second external electrode  4  and are capable of disconnecting each of the capacitor elements C 1  to C 19.

FIELD OF THE ART

The present invention relates to a chip capacitor and a method formanufacturing the same.

BACKGROUND ART

Patent Document 1 discloses a laser trimmable capacitor in which adielectric layer is formed via an internal electrode on a top surface ofa base substrate and a laser trimmable upper electrode is formed on thedielectric layer so as to face the internal electrode. A portion of theupper electrode is removed by a laser to make the electrostaticcapacitance between the electrodes take on a desired value.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: Japanese Patent Application Publication No.    2001-284166

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

With the above arrangement, when capacitors of a plurality of types ofcapacitance values are required, a plurality of types of capacitorscorresponding to the plurality of capacitance values need to be designedindividually. A long period of time is thus required for design and muchlabor is required therefor. Moreover, when a specification of anequipment in which a capacitor is installed is changed and a capacitorof a new capacitance value becomes necessary, this cannot beaccommodated rapidly.

An object of the present invention is to provide a chip capacitorcapable of easily and rapidly accommodating a plurality of types ofcapacitance values using a common design and a method for manufacturingthe chip capacitor.

Means for Solving the Problem

A first aspect of the present invention provides a chip capacitorincluding a substrate, a first external electrode disposed on thesubstrate, a second external electrode disposed on the substrate, aplurality of capacitor elements, respectively including a firstelectrode film formed on the substrate, a first capacitance film formedon the first electrode film, a second electrode film formed on the firstcapacitance film so as to face the first electrode film, a secondcapacitance film formed on the second electrode film, and a thirdelectrode film formed on the second capacitance film so as to face thesecond electrode film, and being connected between the first externalelectrode and the second external electrode, and a plurality of fusesthat are formed on the substrate, are each interposed between theplurality of capacitor elements and the first external electrode or thesecond external electrode, and are capable of disconnecting each of theplurality of capacitor elements.

With this arrangement, the plurality of capacitor elements are connectedbetween the first and second external electrodes disposed on thesubstrate. The plurality of fuses that are capable of disconnecting eachof the plurality of capacitor elements are provided between theplurality of capacitor elements and the first or second externalelectrodes. A plurality of types of capacitance values can thus beaccommodated easily and rapidly by selecting and cutting one or aplurality of the fuses. In other words, a common design can be appliedto chip capacitors of a plurality of types of capacitance values.

Further with the present invention, one capacitor structure is formed bythe first electrode film, the first capacitance film, and the secondelectrode film, and another capacitor structure is formed by the secondelectrode film, the second capacitance film, and the third electrodefilm. Multilayer capacitor structures are thus formed on the substrateto enable the chip capacitor to be made high in capacitance. That is, ahigh capacitance capacitor can be provided even with a small substratesize and a more compact chip capacitor can be provided for the samecapacitance.

A second aspect of the present invention provides the chip capacitoraccording to the first aspect, where the plurality of capacitor elementshave mutually different capacitance values. With this arrangement, chipcapacitors of various capacitance values can be realized with a commondesign by combining a plurality of the capacitor elements that differ incapacitance value. A third aspect of the present invention provides thechip capacitor according to the second aspect, where the capacitancevalues of the plurality of capacitor elements are set to form ageometric progression. With this arrangement, the capacitance value ofthe chip capacitor can be adjusted accurately to a desired capacitancevalue by appropriate selection of a plurality of the capacitor elementsto be connected between the first external electrode and the secondexternal electrode. For example, by setting the common ratio of thegeometric progression to 2, the capacitance value of the chip capacitorcan be adjusted at the precision of the first term of the geometricprogression (term of the smallest value in the geometric progression).

A fourth aspect of the present invention provides the chip capacitoraccording to any one of the first to third aspects, where at least oneof the plurality of fuses is cut. With the chip capacitor that has beenadjusted in capacitance value, one or a plurality of the fuses may becut. The capacitor elements to be connected between the first externalelectrode and the second external electrode can be selected by fusecutting and the chip capacitor of the required capacitance value canthereby be realized.

A fifth aspect of the present invention provides the chip capacitoraccording to any one of the first to fourth aspects, where the secondelectrode film is divided into a plurality of second electrode filmportions and the plurality of fuses are connected respectively to theplurality of the second electrode film portions. With this arrangement,a capacitor structure is arranged by the first capacitance film beingsandwiched between the first electrode film and the second electrodefilm, and another capacitor structure is arranged by the secondcapacitance film being sandwiched between the second electrode film andthe third electrode film. The second electrode film is divided into theplurality of second electrode film portions, the respective secondelectrode film portions thus face the first and third electrode films,and the plurality of capacitor elements are thereby provided on thesubstrate. The chip capacitor having the required capacitance value canbe arranged by cutting the fuses corresponding to the relevant secondelectrode film portions of the plurality of capacitor elements.

A sixth aspect of the present invention provides the chip capacitoraccording to the fifth aspect, where the plurality of second electrodefilm portions face the first electrode film and the third electrode filmover mutually different facing areas. With this arrangement, theplurality of capacitor elements corresponding to the plurality of secondelectrode film portions that mutually differ in facing area havemutually different capacitance values. Chip capacitors of a plurality oftypes of capacitance values can thus be realized by appropriatecombination of the capacitor elements. More specifically, when the fusescorresponding to the capacitor elements other than the selectedplurality of the capacitor elements are cut, the fuses are disconnectedfrom between the first and second external electrodes. The disconnectionenables the chip capacitor to have the required capacitance value.

A seventh aspect of the present invention provides the chip capacitoraccording to the sixth aspect, where the facing areas of the pluralityof second electrode film portions are set to form a geometricprogression. With this arrangement, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting.

An eighth aspect of the present invention provides the chip capacitoraccording to any one of the first to seventh aspects, where the firstelectrode film is divided into a plurality of first electrode filmportions and the plurality of fuses are connected respectively to theplurality of the first electrode film portions. With this arrangement,the first electrode film is divided into the plurality of firstelectrode film portions, the respective first electrode film portionsthus face the second electrode film, and the plurality of capacitorelements are thereby provided on the substrate. The chip capacitorhaving the required capacitance value can be arranged by cutting thefuses corresponding to the relevant first electrode film portions of theplurality of capacitor elements.

A ninth aspect of the present invention provides the chip capacitoraccording to the eighth aspect, where the plurality of first electrodefilm portions face the second electrode film over mutually differentfacing areas. With this arrangement, the plurality of capacitor elementscorresponding to the plurality of first electrode film portions thatmutually differ in facing area have mutually different capacitancevalues. Chip capacitors of a plurality of types of capacitance valuescan thus be realized by appropriate combination of the capacitorelements. More specifically, when the fuses corresponding to thecapacitor elements other than the selected plurality of the capacitorelements are cut, the fuses are disconnected from between the first andsecond external electrodes. The disconnection enables the chip capacitorto have the required capacitance value.

A tenth aspect of the present invention provides the chip capacitoraccording to the ninth aspect, where the facing areas of the pluralityof first electrode film portions are set to form a geometricprogression. With this arrangement, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting.

An eleventh aspect of the present invention provides the chip capacitoraccording to any one of the first to tenth aspects, where the thirdelectrode film is divided into a plurality of third electrode filmportions and the plurality of fuses are connected respectively to theplurality of the third electrode film portions. With this arrangement,the third electrode film is divided into the plurality of thirdelectrode film portions, the respective third electrode film portionsthus face the second electrode film, and the plurality of capacitorelements are thereby provided on the substrate. The chip capacitorhaving the required capacitance value can be arranged by cutting thefuses corresponding to the relevant third electrode film portions of theplurality of capacitor elements.

A twelfth aspect of the present invention provides the chip capacitoraccording to the eleventh aspect, where the plurality of third electrodefilm portions face the second electrode film over mutually differentfacing areas. With this arrangement, the plurality of capacitor elementscorresponding to the plurality of third electrode film portions thatmutually differ in facing area have mutually different capacitancevalues. Chip capacitors of a plurality of types of capacitance valuescan thus be realized by appropriate combination of the capacitorelements. More specifically, when the fuses corresponding to thecapacitor elements other than the selected plurality of the capacitorelements are cut, the fuses are disconnected from between the first andsecond external electrodes. The disconnection enables the chip capacitorto have the required capacitance value.

A thirteenth aspect of the present invention provides the chip capacitoraccording to the twelfth aspect, where the facing areas of the pluralityof third electrode film portions are set to form a geometricprogression. With this arrangement, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by cutting the fuses.

A fourteenth aspect of the present invention provides the chip capacitoraccording to any one of the first to thirteenth aspects, where theplurality of fuses are disposed with the positions thereof being shiftedso as not to overlap with each other in a plan view of looking down at aprincipal surface of the substrate perpendicularly. With thisarrangement, just the desired fuse can be cut by irradiating laser lightfrom a direction perpendicular to the principal surface of the substrateand erroneous cutting of another fuse can be avoided. The capacitancevalue of the chip capacitor can thereby be adjusted reliably to thetarget value.

A fifteenth aspect of the present invention provides the chip capacitoraccording to any one of the fifth to thirteenth aspects, where the firstelectrode film, the second electrode film, or the third electrode film,and the fuses are formed of films of the same conductive material. Withthis arrangement, the electrode film portions and the fuses can bearranged from a conductive material film in common. Each electrode filmportion can be disconnected by cutting the fuse corresponding to theelectrode film portion.

A sixteenth aspect of the present invention provides a method formanufacturing a chip capacitor including a step of forming a pluralityof capacitor elements on a substrate, a step of forming a first externalelectrode and a second external electrode on the substrate, and a stepof forming, on the substrate, a plurality of fuses that disconnectablyconnect each of the plurality of capacitor elements to the firstexternal electrode or the second external electrode, and where the stepof forming the plurality of capacitor elements includes a step offorming a first electrode film on the substrate, a step of forming afirst capacitance film on the first electrode film, a step of forming asecond electrode film on the first capacitance film so as to face thefirst electrode film, a step of forming a second capacitance film on thesecond electrode film, a step of forming a third electrode film on thesecond capacitance film so as to face the second electrode film, and astep of dividing at least one among the first electrode film, the secondelectrode film, and the third electrode film into a plurality ofelectrode film portions.

By this method, chip capacitors being of a common design and yet beingof a plurality of capacitance values can be manufactured by cutting thefuses that are selected in accordance with the required capacitancevalues. Also, a high capacitance capacitor can be provided even with asmall substrate size and a more compact chip capacitor can be providedfor the same capacitance.

A seventeenth aspect of the present invention provides the method formanufacturing a chip capacitor according to the sixteenth aspect, wherethe fuses are formed so as to be connected respectively to the pluralityof electrode film portions. By this method, the chip capacitor havingthe required capacitance value can be arranged by cutting the fusescorresponding to the relevant electrode film portions of the pluralityof capacitor elements provided on the substrate by means of theplurality of electrode film portions.

An eighteenth aspect of the present invention provides the method formanufacturing a chip capacitor according to the sixteenth or seventeenthaspect, where the plurality of electrode film portions are formed so asto face the electrode film, being faced across the first capacitancefilm or the second capacitance film, over mutually different facingareas. By this method, the plurality of electrode film portions are madeto face the electrode film over mutually different facing areas toenable the plurality of capacitor elements differing in capacitancevalue to be formed on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thus be manufactured by appropriatelyselecting and combining the capacitor elements of different capacitancevalues.

A nineteenth aspect of the present invention provides the method formanufacturing a chip capacitor according to the eighteenth aspect, wherethe facing areas of the plurality of electrode film portions are set toform a geometric progression. By this method, the plurality of capacitorelements with capacitance values being set to form a geometricprogression can be formed on the substrate. Therefore, chip capacitorsof a plurality of types of capacitance values can be provided andaccurate adjustment to the desired capacitance value can be achieved byappropriately selecting and combining a plurality of capacitor elements.

A twentieth aspect of the present invention provides the method formanufacturing a chip capacitor according to any one of the sixteenth tonineteenth aspects, where the plurality of fuses are formed with thepositions thereof being shifted so as not to overlap with each other ina plan view of looking down at a principal surface of the substrateperpendicularly. By this method, just the desired fuse can be cut byirradiating laser light from a direction perpendicular to the principalsurface of the substrate and erroneous cutting of another fuse can beavoided. The capacitance value of the chip capacitor can thereby beadjusted reliably to the target value.

A twenty-first aspect of the present invention provides the method formanufacturing a chip capacitor according to any one of the sixteenth totwentieth aspects, where the first electrode film, the second electrodefilm, or the third electrode film, and the fuses are formed of films ofthe same conductive material. By this method, the electrode filmportions and the fuses can be formed of films of the same conductivematerial and can therefore be formed by patterning the same film. Themanufacturing process is thereby simplified.

A twenty-second aspect of the present invention provides the method formanufacturing a chip capacitor according to any one of the sixteenth totwenty-first aspects further including a fuse cutting step of cutting atleast one of the plurality of fuses. By this method, the capacitancevalue of the chip capacitor can be adjusted to the desired capacitancevalue by appropriately selecting each fuse to be cut. That is, the chipcapacitor adjusted to the desired capacitance value can be manufacturedby appropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected.

A twenty-third aspect of the present invention provides the method formanufacturing a chip capacitor according to the twenty-second aspect,further including a step of measuring a total capacitance value of theplurality of capacitor elements and a step of selecting each fuse to becut based on the measured total capacitance value, and where eachselected fuse is cut in the fuse cutting step. By this method, the totalcapacitance value of the plurality of capacitor elements is measured,each fuse to be cut is selected based on the measurement result, andtherefore the capacitance value of the chip capacitor can be set to thetargeted capacitance value reliably.

A twenty-fourth aspect of the present invention provides the method formanufacturing a chip capacitor according to the twenty-second ortwenty-third aspect, further including a step of forming, after cuttingthe fuse or fuses, a protective film covering the cut portion of eachfuse. By this method, the cut portion of each fuse is covered by theprotective film and therefore entry of foreign matter and moisture withrespect to the cut portion can be avoided to enable a chip capacitor,which can realize a plurality of types of capacitance values with acommon design and is high in reliability, to be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a chip capacitor according to a first preferredembodiment of the present invention.

FIG. 2 is a sectional view taken along section line II-II in FIG. 1.

FIG. 3 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 4 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 5 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 6A, FIG. 6B, and FIG. 6C are sectional views for describing stepsrelated to the cutting of a fuse.

FIG. 7 is a plan view for describing the arrangement of a chip capacitoraccording to a second preferred embodiment of the present invention.

FIG. 8 is an exploded perspective view for describing the arrangement ofa chip capacitor according to a third preferred embodiment of thepresent invention.

FIG. 9 is a schematic plan view of the chip capacitor according to athird preferred embodiment of the present invention.

FIG. 10 is a plan view of a chip capacitor according to a firstpreferred embodiment of a first reference example.

FIG. 11 is a sectional view taken along section line XI-XI in FIG. 10.

FIG. 12 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 13 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 14 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 15A, FIG. 15B, and FIG. 15C are sectional views for describingsteps related to the cutting of a fuse.

FIG. 16 is a plan view for describing the arrangement of a chipcapacitor according to a second preferred embodiment of the firstreference example.

FIG. 17 is an exploded perspective view for describing the arrangementof a chip capacitor according to a third preferred embodiment of thefirst reference example.

FIG. 18 is a plan view of a chip capacitor according to a firstpreferred embodiment of a second reference example.

FIG. 19 is a sectional view taken along section line IXX-IXX in FIG. 19.

FIG. 20 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 21 is an electrical equivalent circuit diagram of the chipcapacitor.

FIG. 22 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 23 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 24A, FIG. 24B, and FIG. 24C are sectional views for describingsteps related to the cutting of a fuse.

FIG. 25 is a plan view for describing the arrangement of a chipcapacitor according to a second preferred embodiment of the secondreference example.

FIG. 26 is an exploded perspective view for describing the arrangementof a chip capacitor according to a third preferred embodiment of thesecond reference example.

FIG. 27 is a plan view of a chip capacitor according to a firstpreferred embodiment of a third reference example.

FIG. 28 is a sectional view taken along section line XXVIII-XXVIII inFIG. 27.

FIG. 29 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 30 shows electrical equivalent circuit diagrams of the chipcapacitor.

FIG. 31 is a graph of impedance characteristics of the chip capacitor.

FIG. 32 is a diagram of a chip shape showing the size of an effectiveresistance region of the substrate.

FIG. 33 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 34 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 35A, FIG. 35B, and FIG. 35C are sectional views for describingsteps related to the cutting of a fuse.

FIG. 36 is a plan view for describing the arrangement of a chipcapacitor according to a second preferred embodiment of the thirdreference example.

FIG. 37 is an exploded perspective view for describing the arrangementof a chip capacitor according to a third preferred embodiment of thethird reference example.

FIG. 38 is a plan view of a chip capacitor according to a firstpreferred embodiment of a fourth reference example.

FIG. 39 is a sectional view taken along section line XXXIX-XXXIX in FIG.38.

FIG. 40 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 41 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 42 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 43A, FIG. 43B, and FIG. 43C are sectional views for describingsteps related to the cutting of a fuse.

FIG. 44 is a plan view for describing the arrangement of a chipcapacitor according to a second preferred embodiment of the fourthreference example.

FIG. 45 is a sectional view for describing the arrangement of a chipcapacitor according to a third preferred embodiment of the fourthreference example.

FIG. 46 is an exploded perspective view showing the arrangement of aportion of the chip capacitor of FIG. 45 in a separated state.

FIG. 47 is a sectional view for describing the arrangement of a chipcapacitor according to a fourth preferred embodiment of the fourthreference example.

FIG. 48 is a plan view of a chip capacitor according to a firstpreferred embodiment of a fifth reference example.

FIG. 49 is a sectional view taken along section line XLIX-XLIX in FIG.48.

FIG. 50 is an exploded perspective view showing the arrangement of aportion of the chip capacitor in a separated state.

FIG. 51 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor.

FIG. 52 is a flow diagram for describing an example of a process formanufacturing the chip capacitor.

FIG. 53A, FIG. 53B, and FIG. 53C are sectional views for describingsteps related to the cutting of a fuse.

FIG. 54 is a plan view for describing the arrangement of a chipcapacitor according to a second preferred embodiment of the fifthreference example.

FIG. 55 is an exploded perspective view for describing the arrangementof a chip capacitor according to a third preferred embodiment of thefifth reference example.

MODES FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention shall now be described indetail with reference to the attached drawings. FIG. 1 is a plan view ofa chip capacitor according to a first preferred embodiment of thepresent invention, and FIG. 2 is a sectional view thereof and shows asection taken along section line II-II in FIG. 1. Further, FIG. 3 is anexploded perspective view showing the arrangement of a portion of thechip capacitor in a separated state. The chip capacitor 1 includes asubstrate 2, a first external electrode 3 disposed on the substrate 2,and a second external electrode 4 disposed similarly on the substrate 2.In the present preferred embodiment, the substrate 2 has, in a plan viewof looking down at a principal surface (top surface) 2A of the substrate2 perpendicularly, a rectangular shape with the four corners chamfered.The first external electrode 3 and the second external electrode 4 arerespectively disposed at portions at respective ends in the longdirection of the substrate 2. In the present preferred embodiment, eachof the first external electrode 3 and the second external electrode 4has a substantially rectangular planar shape extending in the shortdirection of the substrate 2 and has chamfered portions at two locationsrespectively corresponding to the corners of the substrate 2. On thesubstrate 2, a plurality of capacitor elements C1 to C19 are disposedwithin a capacitor arrangement region 5 between the first externalelectrode 3 and the second external electrode 4. The plurality ofcapacitor elements C1 to C19 are electrically connected respectively tothe first external electrode 3 via a plurality of fuse units 7 (fuses).In the present preferred embodiment, the capacitor element C11 ispositioned directly above the capacitor element C1, and similarly, eachof the capacitor elements C12 to C19 is positioned directly above thecorresponding capacitor element (the capacitor element with the numeralat the end of the symbol being the same) among the capacitor elements C2to C9. The present chip capacitor 1 thus has capacitor structures ofmultiple layers (two layers in the present case) of vertically laminatedcapacitor elements.

As shown in FIG. 2 and FIG. 3, an insulating film 8 is formed on the topsurface of the substrate 2, and a first electrode film 11 is formed onthe top surface of the insulating film 8. The first electrode film 11 isformed to spread across substantially the entirety of the capacitorarrangement region 5 and extend to a region directly below the secondexternal electrode 4. More specifically, the first electrode film 11 hasa capacitor electrode region 11A functioning as a lower electrode incommon to the capacitor elements C1 to C9 and a pad region 11B forleading out to an external electrode. The capacitor electrode region 11Ais positioned in the capacitor arrangement region 5 and the pad region11B is positioned directly below the second external electrode 4.

In the capacitor arrangement region 5, a first capacitance film(dielectric film) 12 is formed so as to cover the first electrode film11 (capacitor electrode region 11A). The first capacitance film 12 iscontinuous across the entirety of the capacitor electrode region 11Aand, in the present preferred embodiment, further extends to a regiondirectly below the first external electrode 3 and covers the insulatingfilm 8 outside the capacitor arrangement region 5. A second electrodefilm (capacitance adjustment electrode film) 13 is formed on the firstcapacitance film 12. In FIG. 1, the second electrode film 13 is coloredfor the sake of clarity. The second electrode film 13 includes acapacitor electrode region 13A positioned in the capacitor arrangementregion 5, a pad region 13B positioned directly below the first externalelectrode 3, and a fuse region 13C disposed between the pad region 13Band the capacitor electrode region 13A.

In the capacitor electrode region 13A, the second electrode film 13 isdivided into a plurality of (second) electrode film portions 131 to 139.In the present preferred embodiment, the respective electrode filmportions 131 to 139 are all formed to rectangular shapes and extend inthe form of bands from the fuse region 13C toward the second externalelectrode 4. The plurality of electrode film portions 131 to 139 facethe first electrode film 11 across the first capacitance film 12 over aplurality of types of mutually different facing areas. Morespecifically, a ratio of the facing areas of the electrode film portions131 to 139 with respect to the first electrode film 11 may be set to be1:2:4:8:16:32:64:128:128. That is, the plurality of electrode filmportions 131 to 139 include the plurality of electrode film portionsdiffering in facing area and more specifically include the plurality ofelectrode film portions 131 to 138 (or 131 to 137 and 139) having facingareas (with respect to the first electrode film 11) that are set to forma geometric progression with a common ratio of 2. The plurality ofcapacitor elements C1 to C9, respectively arranged by the respectiveelectrode film portions 131 to 139 and the facing first electrode film11 across the first capacitance film 12, thus include the plurality ofcapacitor elements having mutually different capacitance values. If theratio of the facing areas of the electrode film portions 131 to 139 isas mentioned above, the ratio of the capacitance values of the capacitorelements C1 to C9 is equal to the ratio of the facing areas and is1:2:4:8:16:32:64:128:128. The plurality of capacitor elements C1 to C9thus include the plurality of capacitor elements C1 to C8 (or C1 to C7and C9) with capacitance values set to form the geometric progressionwith the common ratio of 2.

In the present preferred embodiment, the electrode film portions 131 to135 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4:8:16. Also, the electrode filmportions 135, 136, 137, 138, and 139 are formed to bands that are equalin length and have widths with the ratio thereof being set to 1:2:4:8:8.The electrode film portions 135 to 139 are formed to extend across arange from an end edge at the first external electrode 3 side to an endedge at the second external electrode 4 side of the capacitorarrangement region 5, and the electrode film portions 131 to 134 areformed to be shorter than this range.

The pad region 13B is formed to be substantially similar in shape to thefirst external electrode 3 and has a substantially rectangular planarshape having two chamfered portions corresponding to corner portions ofthe substrate 2. The fuse region 13C is disposed along one long side(the long side at the inner side with respect to the peripheral edge ofthe substrate 2) of the pad region 13B. The fuse region 13C includes theplurality of fuse units 7 that are aligned along the one long side ofthe pad region 13B. The fuse units 7 are formed of the same material asand to be integral to the pad region 13B of the second electrode film13. The plurality of electrode film portions 131 to 139 are each formedintegral to one or a plurality of the fuse units 7, are connected to thepad region 13B via the fuse units 7, and are electrically connected tothe first external electrode 3 via the pad region 13B. Each of theelectrode film portions 131 to 136 of comparatively small area isconnected to the pad region 13B via a single fuse unit 7, and each ofthe electrode film portions 137 to 139 of comparatively large area isconnected to the pad region 13B via a plurality of fuse units 7. It isnot necessary for all of the fuse units 7 to be used and, in the presentpreferred embodiment, a portion of the fuse units 7 is unused.

The fuse units 7 include first wide portions 7A arranged to be connectedto the pad region 13B, second wide portions 7B arranged to be connectedto the electrode film portions 131 to 139, and narrow portions 7Cconnecting the first and second wide portions 7A and 7B. The narrowportions 7C are arranged to be capable of being cut (fused) by laserlight. Unnecessary electrode film portions among the electrode filmportions 131 to 139 can thus be electrically disconnected from the firstand second external electrodes 3 and 4 by cutting the fuse units 7.

As shown in FIG. 2, a second capacitance film (dielectric film) 17 isformed so as to cover the second electrode film 13. The secondcapacitance film 17 is continuous across the entirety of the secondelectrode film 13 and, in the present preferred embodiment, furthercovers a portion of the first capacitance film 12 on which the secondelectrode film 13 is not disposed. A third electrode film 16 is formedon the second capacitance film 17. The third electrode film 16 has acapacitor electrode region 16A positioned in the capacitor arrangementregion 5 and a pad region 16B positioned directly above (in anoverlapping region in a plan view of) the pad region 11B of the firstelectrode film 11.

In this case, in the capacitor arrangement region 5, the capacitorelectrode region 11A of the first electrode film 11 and the capacitorelectrode region 13A of the second electrode film 13 face each otheracross the first capacitance film 12, and the capacitor electrode region13A of the second electrode film 13 and the capacitor electrode region16A of the third electrode film 16 face each other across the secondcapacitance film 17. Also, the plurality of electrode film portions 131to 139 (see FIG. 1) in the capacitor electrode region 13A of the secondelectrode film 13 face the third electrode film 16 across the secondcapacitance film 17 over a plurality of types of mutually differentfacing areas. More specifically, as in the case with respect to thefirst electrode film 11, the ratio of the facing areas of the electrodefilm portions 131 to 139 with respect to the third electrode film 16 maybe set to be 1:2:4:8:16:32:64:128:128. That is, the plurality ofelectrode film portions 131 to 139 include the plurality of electrodefilm portions differing in facing area and more specifically include theplurality of electrode film portions 131 to 138 (or 131 to 137 and 139)having facing areas (with respect to the third electrode film 16) thatare set to form a geometric progression with a common ratio of 2. Theplurality of capacitor elements C11 to C19, respectively arranged by therespective electrode film portions 131 to 139 and the facing thirdelectrode film 16 across the second capacitance film 17, thus includethe plurality of capacitor elements having mutually differentcapacitance values. If the ratio of the facing areas of the electrodefilm portions 131 to 139 is as mentioned above, the ratio of thecapacitance values of the capacitor elements C11 to C19 is equal to theratio of the facing areas and is 1:2:4:8:16:32:64:128:128. The pluralityof capacitor elements C11 to C19 thus include the plurality of capacitorelements C11 to C18 (or C11 to C17 and C19) with capacitance values setto form the geometric progression with the common ratio of 2.

In the present preferred embodiment, each of the capacitor elements C1to C9 and the corresponding capacitor element (the capacitor elementwith the numeral at the end of the symbol being the same) among thecapacitor elements C11 to C19 share the electrode film portion in commonamong the electrode film portions 131 to 138 and therefore have equalcapacitance values. Therefore with the chip capacitor 1, a singlecapacitor structure is formed by the first electrode film 11, the firstcapacitance film 12, and the second electrode film 13, and anothercapacitance structure is formed by the second electrode film 13, thesecond capacitance film 17, and the third electrode film 16. That is,capacitor structures of multiple layers (two layers in the present case)are formed on the substrate 2 and the chip capacitor 1 can thus be madehigh in capacitance. That is, a high capacitance capacitor can beprovided even if the size of the substrate 2 is small and a more compactchip capacitor 1 can be provided for the same capacitance.

Although omitted from illustration in FIG. 1 and FIG. 3, the top surfaceof the chip capacitor 1 that includes the top surface of the thirdelectrode film 16 is covered by a passivation film 9 as shown in FIG. 2.The passivation film 9 is constituted, for example, of a nitride filmand is formed not only to cover the upper surface of the chip capacitor1 but also to extend to side surfaces of the substrate 2 and cover theside surfaces. Further, a resin film 10, made of a polyimide resin,etc., is formed on the passivation film 9. The resin film 10 is formedto cover the upper surface of the chip capacitor 1 and extend to theside surfaces of the substrate 2 to cover the passivation film 9 on theside surfaces.

The passivation film 9 and the resin film 10 are protective films thatprotect the top surface of the chip capacitor 1. In these films, padopenings 21 and 22 are respectively formed in regions corresponding tothe first external electrode 3 and the second external electrode 4. Thepad opening 21 corresponds to the first external electrode 3 andpenetrates through the passivation film 9, the resin film 10, and thesecond capacitance film 17 so as to expose a region of a portion of thepad region 13B of the second electrode film 13. The pad opening 22corresponds to the second external electrode 4 and penetrates throughthe passivation film 9, the resin film 10, the third electrode film 16,the first capacitance film 12, and the second capacitance film 17 so asto expose regions of portions of the pad region 11B of the firstelectrode film 11 and the pad region 16B of the third electrode film 16.

The first external electrode 3 and the second external electrode 4 arerespectively embedded in the pad openings 21 and 22. The first externalelectrode 3 is thereby bonded to the pad region 13B of the secondelectrode film 13 and the second external electrode 4 is bonded to thepad region 11B of the first electrode film 11 and the pad region 16B ofthe third electrode film 16. The first and second external electrodes 3and 4 are formed to project from the top surface of the resin film 10.The chip capacitor 1 can thereby be flip-chip bonded to a mountingsubstrate.

FIG. 4 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor 1. The plurality of capacitor elements C1to C19 are connected in parallel between the first external electrode 3and the second external electrode 4. Fuses F1 to F9, each arranged fromone or a plurality of the fuse units 7, are interposed in series betweenthe respective capacitor elements C1 to C19 and the first externalelectrode 3. Specifically, each pair of vertically overlapping capacitorelements (the capacitor elements with the numeral at the end of thesymbols being the same) are connected to the first external electrode 3(an interval between first external electrode 3 and the second externalelectrode 4) via a common fuse. For example, the pair of capacitorelements C1 and C11 are connected to the first external electrode 3 viathe common fuse F1.

When all of the fuses F1 to F9 are connected, the capacitance value ofthe chip capacitor 1 is equal to the total of the capacitance values ofthe capacitor elements C1 to C19. When one or two or more fuses selectedfrom among the plurality of fuses F1 to F19 is or are cut, each pair ofcapacitor elements corresponding to a cut fuse are disconnected and thecapacitance value of the chip capacitor 1 decreases by just thecapacitance value of the disconnected pair or pairs of capacitorelements. For example, when the fuse F1 is cut, the corresponding pairof capacitor elements C1 and C11 are disconnected and the capacitancevalue of the chip capacitor 1 decreases by just the capacitance value ofthe disconnected pair of capacitor elements.

Therefore by measuring the capacitance value across the pad regions 11B(16B) and 13B (the total capacitance value of the capacitor elements C1to C19) and thereafter using laser light to fuse one or a plurality offuses selected appropriately from among the fuses F1 to F9 in accordancewith a desired capacitance value, adjustment (laser trimming) to thedesired capacitance value can be performed. In particular, if thecapacitance values of the capacitor elements C1 to C8 (C11 to C18) areset to form a geometric progression with a common ratio of 2, fineadjustment to the targeted capacitance value at a precisioncorresponding to the capacitance value of the capacitor element C1,which is the smallest capacitance value (value of the first term in thegeometric progression), is made possible.

For example, the capacitance values of the capacitor elements C1 to C19may be set as follows. As mentioned above, each of the capacitorelements C1 to C9 and the corresponding capacitor element (the capacitorelement with the numeral at the end of the symbol being the same) amongthe capacitor elements C11 to C19 have equal capacitance values.C1=C11=0.03125 pF C2=C12=0.0625 pF C3=C13=0.125 pF C4=C14=0.25 pFC5=C15=0.5 pF C6=C16=1 pF C7=C17=2 pF C8=C18=4 pF C9=C19=4 pF. In thiscase, the capacitance of the chip capacitor 1 can be finely adjusted ata minimum adjustment precision of 0.03125 pF. Also, the fuses to be cutfrom among the fuses F1 to F9 can be selected appropriately to providethe chip capacitor 1 with an arbitrary capacitance value between 0.1 pFand 20 pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C19 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 3 and the secondexternal electrode 4. The capacitor elements C1 to C19 include aplurality of capacitor elements that differ in capacitance value andmore specifically include a plurality of capacitor elements withcapacitance values set to form a geometric progression. The chipcapacitor 1, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Details of respective portions of the chip capacitor 1 shall now bedescribed. With reference to FIG. 1, the substrate 2 may have, forexample, a rectangular shape of 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2mm×0.1 mm, etc. (preferably a size of not more than 0.4 mm×0.2 mm) in aplan view. The capacitor arrangement region 5 is generally a squareregion with each side having a length corresponding to the length of theshort side of the substrate 2. The thickness of the substrate 2 may beapproximately 150 μm. The substrate 2 may, for example, be a substratethat has been thinned by grinding or polishing from a rear surface side(surface on which the capacitor elements C1 to C19 are not formed). Asthe material of the substrate 2, a semiconductor substrate asrepresented by a silicon substrate may be used or a glass substrate maybe used or a resin film may be used.

With reference to FIG. 2, the insulating film 8 may be a silicon oxidefilm or other oxide film. The film thickness thereof may beapproximately 500 Å to 2000 Å. The first electrode film 11 is preferablya conductive film, a metal film in particular, and may, for example, bean aluminum film. The first electrode film 11 that is constituted of analuminum film may be formed by a sputtering method. Similarly, thesecond electrode film 13 is preferably constituted of a conductive film,a metal film in particular, and may be an aluminum film. The secondelectrode film 13 that is constituted of an aluminum film may be formedby the sputtering method. The patterning for dividing the capacitorelectrode region 13A of the second electrode film 13 into the electrodefilm portions 131 to 139 and shaping the fuse region 13C into theplurality of fuse units 7 may be performed by photolithography andetching processes. The third electrode film 16 is preferably constitutedof a conductive film, a metal film in particular, and may be an aluminumfilm. The third electrode film 16 that is constituted of an aluminumfilm may be formed by a sputtering method.

At least any one of (in the present case, all of) the first electrodefilm 11, the second electrode film 13, and the third electrode film 16is thus formed of a film of the same conductive material as the fuseunits 7. In this case, the electrode film or films and the fuse unit 7can be formed of films of the same conductive material and themanufacturing process is simplified because these can be formed bypatterning the same film.

The first capacitance film 12 and the second capacitance film 17 may beconstituted, for example, of silicon nitride films, and the filmthicknesses thereof may be 500 Å to 2000 Å (for example, 1000 Å). Thefirst capacitance film 12 and the second capacitance film 17 may besilicon nitride films formed by plasma CVD (chemical vapor deposition).

The passivation film 9 may be constituted, for example, of a siliconnitride film and may be formed, for example, by the plasma CVD method.The film thickness thereof may be approximately 8000 Å. As mentionedabove, the resin film 10 may be constituted of a polyimide film or otherresin film.

Each of the first and second external electrodes 3 and 4 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the first electrode film 11 (third electrode film16) or the second electrode film 13, a palladium layer laminated on thenickel layer, and a gold layer laminated on the palladium layer arelaminated, and may be formed, for example, by a plating method (or morespecifically, an electroless plating method). The nickel layercontributes to improvement of adhesion with the first electrode film 11(third electrode film 16) or the second electrode film 13, and thepalladium layer functions as a diffusion preventing layer thatsuppresses mutual diffusion of the material of the first electrode film11 (third electrode film 16) or the second electrode film 13 and thegold of the uppermost layer of each of the first and second externalelectrodes 3 and 4.

FIG. 5 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 1. The insulating film 8, constitutedof an oxide film (for example, a silicon oxide film), is formed on thetop surface of the substrate 2 by a thermal oxidation method and/or CVDmethod (step S1). Thereafter, the first electrode film 11, constitutedof an aluminum film, is formed over the entire top surface of theinsulating film 8, for example, by the sputtering method (step S2). Thefilm thickness of the first electrode film 11 may be approximately 8000Å. Thereafter, a resist pattern corresponding to the final shape of thefirst electrode film 11 is formed on the top surface of the firstelectrode film 11 by photolithography (step S3). The first electrodefilm 11 is etched using the resist pattern as a mask to obtain the firstelectrode film 11 of the pattern shown in FIG. 3, etc. (step S4). Theetching of the first electrode film 11 may be performed, for example, byreactive ion etching.

Thereafter, the first capacitance film 12, constituted of a siliconnitride film, etc., is formed on the first electrode film 11, forexample, by the plasma CVD method (step S5). In the region in which thefirst electrode film 11 is not formed, the first capacitance film 12 isformed on the top surface of the insulating film 8. Thereafter, thesecond electrode film 13 is formed on the first capacitance film 12(step S6). The second electrode film 13 is constituted, for example, ofan aluminum film and may be formed by the sputtering method. The filmthickness thereof may be approximately 8000 Å. Thereafter, a resistpattern corresponding to the final shape of the second electrode film 13is formed on the top surface of the second electrode film 13 byphotolithography (step S7). The second electrode film 13 is patterned toits final shape (see FIG. 3, etc.) by etching using the resist patternas a mask (step S8). The second electrode film 13 is thereby shaped tothe pattern having the plurality of electrode film portions 131 to 139in the capacitor electrode region 13A, having the plurality of fuseunits 7 in the fuse region 13C, and having the pad region 13B connectedto the fuse units 7. The etching for patterning the second electrodefilm 13 may be performed by wet etching using an etching liquid, such asphosphoric acid, etc., or may be performed by reactive ion etching.

Thereafter, the second capacitance film 17, constituted of a siliconnitride film, etc., is formed on the second electrode film 13, forexample, by the plasma CVD method (step S9). In the region in which thesecond electrode film 13 is not formed, the second capacitance film 17is formed on the top surface of the first capacitance film 12.Thereafter, the third electrode film 16 is formed on the secondcapacitance film 17 (step S10). Thereafter, a resist patterncorresponding to the final shape of the third electrode film 16 isformed on the top surface of the third electrode film 16 byphotolithography (step S11). The third electrode film 16 is etched usingthe resist pattern as a mask to obtain the third electrode film 16 ofthe pattern having the pad region 16B shown in FIG. 3, etc. (step S12).The etching of the third electrode film 16 may be performed, forexample, by reactive ion etching.

Thereafter, inspection probes are contacted against the pad region 13Bof the second electrode film 13 and the pad region 11B of the firstelectrode film 11 (the pad region 16B of the third electrode film 16) tomeasure the total capacitance value of the plurality of capacitorelements C1 to C19 (step S13). Based on the measured total capacitancevalue, the capacitor elements to be disconnected, that is, the fuses tobe cut are selected in accordance with the targeted capacitance value ofthe chip capacitor 1 (step S14).

Thereafter as shown in FIG. 6A, a cover film 23, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 2 (step S15). The forming of the cover film 23 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 23 covers the patterned third electrode film 16 and, in theregion in which the third electrode film 16 is not formed, covers thefirst capacitance film 12, the second capacitance film 17, the firstelectrode film 11 in the pad region 11B. The cover film 23 covers thefuse units 7 in the fuse region 13C.

From this state, the laser trimming for fusing the fuse units 7 isperformed (step S16). That is, as shown in FIG. 6B, each fuse unit 7constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 24 and thenarrow portion 7C of the fuse unit 7 is fused. The correspondingcapacitor element (capacitor element pair) is thereby disconnected fromthe pad region 13B. When the laser light 24 is irradiated on the fuseunit 7, the energy of the laser light 24 is accumulated at a vicinity ofthe fuse unit 7 by the action of the cover film 23 and the fuse unit 7is thereby fused.

If the second capacitance film 17 has sufficient thickness enabling itto be used as a cover film for accumulating the energy of the laserlight, the forming of the cover film 23 (step S15) immediately beforethe laser trimming may be omitted. Thereafter as shown in FIG. 6C, asilicon nitride film is deposited on the cover film 23, for example, bythe plasma CVD method to form the passivation film 9 (step S17). In thefinal form, the cover film 23 is made integral with the passivation film9 to constitute a portion of the passivation film 9. The passivationfilm 9 that is formed after the cutting of the fuses enters intoopenings in the cover film 23, destroyed at the same time as the fusingof the fuses, to cover and protect the cut surfaces of the fuse units 7.The passivation film 9 thus prevents entry of foreign matter and entryof moisture into the cut locations of the fuse units 7, therebyimproving the reliability of the chip capacitor 1. The passivation film9 may be formed to have a film thickness, for example, of approximately8000 Å as a whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 3 and 4 are to be formed,is formed on the passivation film 9 (step S18). The passivation film 9is etched using the resist pattern as a mask. In this process, thesecond capacitance film 17 is also etched as necessary. The pad openingexposing the first electrode film 11 in the pad region 11B, the padopening exposing the third electrode film 16 in the pad region 16B, andthe pad opening exposing the second electrode film 13 in the pad region13B are thereby formed (step S19). The etching of the passivation film 9may be performed by reactive ion etching.

Thereafter, a resin film is coated on the entire surface (step S20). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S21). The pad openings 21 and 22 penetrating through the resinfilm 10 and the passivation film 9, etc., are thereby formed.Thereafter, heat treatment (curing) for hardening the resin film isperformed (step S22) and further, the first external electrode 3 and thesecond external electrode 4 are grown inside the pad openings 21 and 22,for example, by the electroless plating method (step S23). The chipcapacitor 1 of the structure shown in FIG. 1, etc., is thereby obtained.

In the patterning of the second electrode film 13 using thephotolithography process, the electrode film portions 131 to 139 ofminute areas can be formed with high precision and the fuse units 7 ofeven finer pattern can be formed. After the patterning of the thirdelectrode film 16, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 1 that is accurately adjusted to the desired capacitancevalue can be obtained.

FIG. 7 is a plan view for describing the arrangement of a chip capacitor25 according to a second preferred embodiment of the present invention.In FIG. 7, portions corresponding to respective portions shown in FIG. 1are indicated using the same reference symbols as in FIG. 1. In thefirst preferred embodiment, the capacitor electrode region 13A of thesecond electrode film 13 is divided into the electrode film portions 131to 139 each having a band shape. In this case, regions that cannot beused as capacitor elements are formed within the capacitor arrangementregion 5 as shown in FIG. 1 and effective use cannot be made of therestricted region on the small substrate 2.

Therefore with the preferred embodiment shown in FIG. 7, the pluralityof electrode film portions 131 to 139 are divided into L-shapedelectrode film portions 141 to 149. For example, the electrode filmportion 149 in the arrangement of FIG. 7 can thereby be made to faceeach of the first electrode film 11 and the third electrode film 16 overan area that is 1.5 times that of the electrode film portion 139 in thearrangement of FIG. 1. Therefore, if the capacitor element C9 (C19)corresponding to the electrode film portion 139 in the first preferredembodiment of FIG. 1 has a capacitance of 4 pF, the capacitor element C9(C19) can be made to have a capacitance of 6 pF by use of the electrodefilm portion 149 of the present preferred embodiment. The capacitancevalue of the chip capacitor 25 can thereby be set over a wider range bymaking effective use of the interior of the capacitor arrangement region5.

The process for manufacturing the chip capacitor 25 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 5. However, in the patterning of the second electrode film13 (steps S7 and S8), the capacitor electrode region 13A is divided intothe plurality of electrode film portions 141 to 149 of the shapes shownin FIG. 7. FIG. 8 is an exploded perspective view for describing thearrangement of a chip capacitor 26 according to a third preferredembodiment of the present invention, and the respective portions of thechip capacitor 26 are shown in the same manner as in FIG. 3 used fordescribing the first preferred embodiment.

With the first preferred embodiment, the first electrode film 11 and thethird electrode film 16 respectively have the capacitor electroderegions 11A and 16A that are constituted of patterns that are continuousacross substantially the entirety of the capacitor arrangement region 5,and the capacitor electrode region 13A of the second electrode film 13is divided into the plurality of electrode film portions 131 to 139 (seeFIG. 3). In contrast, with the present preferred embodiment, whereas thecapacitor electrode region 13A of the second electrode film 13 is formedto a continuous film pattern that is continuous across substantially theentirety of the capacitor arrangement region 5, the capacitor electroderegion 11A of the first electrode film 11 is divided into a plurality of(first) electrode film portions 151 to 159 and the capacitor electroderegion 16A of the third electrode film 16 is divided into the pluralityof (third) electrode film portions 181 to 184. The electrode filmportions 151 to 159 may be formed in the same shapes and area ratio asthose of the electrode film portions 131 to 139 in the first preferredembodiment or may be formed in the same shapes and area ratio as thoseof the electrode film portions 141 to 149 in the second preferredembodiment. The electrode film portions 181 to 184 may also be formed inthe same manner as the electrode film portions 151 to 159. That is, theelectrode film portions 151 to 159 may face the second electrode film 13over mutually different facing areas and the facing areas may be set toform a geometric progression. Similarly, the electrode film portions 181to 184 may face the second electrode film 13 over mutually differentfacing areas and the facing areas may be set to form a geometricprogression.

A plurality of capacitor elements C21 to C29 are thus arranged by theelectrode film portions 151 to 159, the first capacitance film 12, andthe second electrode film 13. At least a portion of the plurality ofcapacitor elements C21 to C29 constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression). Further,a plurality of capacitor elements C31 to C34 are arranged by theelectrode film portions 181 to 184, the second capacitance film 17, andthe second electrode film 13. At least a portion of the plurality ofcapacitor elements C31 to C34 constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression).

The first electrode film 11 further has a fuse region 11C between thecapacitor electrode region 11A and the pad region 11B. In the fuseregion 11C, a plurality of fuse units 27, similar to the fuse units 7 ofthe first preferred embodiment, are aligned in a single column along thepad region 11B. Each of the electrode film portions 151 to 159(capacitor elements C21 to C29) is connected to the pad region 11B viaone or a plurality of the fuse units 27. That is, the plurality of fuseunits 27 are each interposed between the capacitor elements C21 to C29and the second external electrode 4 on the pad region 11B. The fuseunits 27 corresponding to the respective capacitor elements C21 to C29constitute fuses F11 to F19 (see FIG. 9).

The third electrode film 16 further has a fuse region 16C between thecapacitor electrode region 16A and the pad region 16B. In the fuseregion 16C, a plurality of fuse units 28, similar to the fuse units 7 ofthe first preferred embodiment, are aligned in a single column along thepad region 16B. Each of the electrode film portions 181 to 184(capacitor elements C31 to C34) is connected to the pad region 16B viaone or a plurality of the fuse units 28. That is, the plurality of fuseunits 28 are each interposed between the capacitor elements C31 to C34and the second external electrode 4 on the pad region 16B. The fuseunits 28 corresponding to the respective capacitor elements C31 to C34constitute fuses F21 to F24 (see FIG. 9).

The plurality of fuse units 27 (fuses F11 to F19) and 28 (fuses F21 toF24) are disposed with the positions thereof being shifted so as not tooverlap with each other in a plan view (see FIG. 9). Specifically, thefuse units 27 and 28 are aligned one by one across intervals along thedirection of extension of the second external electrode 4 (shortdirection of the substrate 2). Therefore, just the desired fuse (fuseunit 27 or 28) can be cut by irradiating laser light 24 (see FIG. 6B)from a direction perpendicular to a principal surface 2A of thesubstrate 2 and erroneous cutting of another fuse can be avoided. Thecapacitance value of the chip capacitor 26 can thereby be adjustedreliably to the target value. The second electrode film 13 must bedisposed so as not to overlap with the fuse units 27 and 28 in a planview to avoid being cut by the laser light 24.

The electrode film portions 151 to 159 face the second electrode film 13across the first capacitance film 12 over mutually different facingareas in the arrangement of the third preferred embodiment as well andany of these can be disconnected individually by cutting the fuse unit27. Similarly, the electrode film portions 181 to 184 face the secondelectrode film 13 across the second capacitance film 17 over mutuallydifferent facing areas and any of these can be disconnected individuallyby cutting the fuse unit 28. The same effects as those of the firstpreferred embodiment are thus obtained. In particular, by forming atleast a portion of the plurality of electrode film portions 151 to 159and at least a portion of the plurality of electrode film portions 181to 184 so as to face the second electrode film 13 over facing areas setto form a geometric progression with a common ratio of 2, a chipcapacitor that is precisely adjusted to the required capacitance valuecan be provided in the same manner as in the first preferred embodiment.

With the first and second preferred embodiments, vertically overlappingcapacitor elements (for example, the capacitor elements C1 and C11) areconnected via a common fuse (the fuse F1 in the case of the capacitorelements C1 and C11) to the first external electrode 3 as describedabove (see FIG. 1 to FIG. 3) and therefore when the common fuse is cut,the upper and lower capacitor elements are disconnected at once. On theother hand, with the third preferred embodiment, each of the capacitorelements C21 to C29 and C31 to C34 is connected via a dedicated fuse(fuse unit 27 or 28) to the second external electrode 4. Each capacitorelement can thus be disconnected individually, the range of combinationof the capacitor elements is thus broadened in comparison to those ofthe first and second preferred embodiments, and the capacitance value ofthe chip capacitor 26 as a whole can thus be set over an even broaderrange. Further, by making the capacitor elements C21 to C29 and C31 toC34 all differ in capacitance value, the capacitance value of the chipcapacitor 26 as a whole can be set over an even broader range.

The process for manufacturing the chip capacitor 26 according to thethird preferred embodiment is practically the same as the process shownin FIG. 5. However, in the patterning of the first electrode film 11(steps S3 and S4), the capacitor electrode region 11A is divided intothe electrode film portions 151 to 159 and the plurality of fuse units27 are formed in the fuse region 11C. Also, in the patterning of thesecond electrode film 13 (steps S7 and S8), a plurality of electrodefilm portions are not formed and fuse units are also not formed. Also inthe patterning of the third electrode film 16 (steps S11 and S12), thecapacitor electrode region 16A is divided into the plurality ofelectrode film portions 181 to 184 and the plurality of fuse units 28are formed in the fuse region 16C. Further, in the laser trimming (stepS16), the selected fuse units among the fuse units 27 formed in thefirst electrode film 11 and the fuse units 28 formed in the thirdelectrode film 16 are cut by laser light.

If just a fuse unit 27 formed in the first electrode film 11 is to besubject to laser trimming, the first electrode film 11 is covered by thefirst capacitance film 12 and the first capacitance film 12 can be usedas a cover film for accumulating the energy of the laser light in theprocess of laser trimming. The forming of the cover film (step S15)immediately before the laser trimming may thus be omitted.

In the third preferred embodiment, the capacitor electrode region 11A ofthe first electrode film 11 and the capacitor electrode region 16A ofthe third electrode film 16 are made to have different shapes bydividing the first electrode film 11 into the nine electrode filmportions 151 to 159 and on the other hand, dividing the third electrodefilm 16 into the four electrode film portions 181 to 184. However, thisis only an example and obviously the capacitor electrode region 11A andthe capacitor electrode region 16A may be mutually matched in shape (thenumber of electrode film portions). However, even in this case, theplurality of fuse units 27 and 28 must be disposed with the positionsthereof being shifted so as not to overlap with each other in a planview (see FIG. 9).

Although preferred embodiments of the present invention have beendescribed above, the present invention may be implemented in yet othermodes as well. For example, although with each of the preferredembodiments described above, the arrangement where just the secondelectrode film 13 is divided into the plurality of electrode films orthe arrangement where the first electrode film 11 and the thirdelectrode film 16 besides the second electrode film 13 are divided intothe plurality of electrode films were described, the first electrodefilm 11, the second electrode film 13, and the third electrode film 16may all be divided into a plurality of electrode film portions. In anyof these cases, the chip capacitor 1 having the required capacitancevalues can be arranged by cutting the fuses (fuse units 7, 27, and 28)corresponding to the relevant electrode film portions (131 to 139, 141to 149, 151 to 159, and 181 to 184) of the plurality of capacitorelements (C1 to C19, C21 to C29, and C31 to C34).

Also with the preferred embodiments, the chip capacitors 1, 25, and 26,each having a two-layer capacitor structure, was described, a chipcapacitor having a capacitor structure of three or more layers may alsobe considered. For example, with the chip capacitor 26 of FIG. 8, a chipcapacitor with a three-layer structure can be realized by forming athird capacitance film on the third electrode film 16 and forming afourth electrode film, connected to the first external electrode 3, onthe third capacitance film. Further, a chip capacitor with a four-layerstructure can be realized by forming a fifth electrode film via a fourthcapacitance film on the fourth electrode film. By arranging a chipcapacitor with such a multilayer structure, the realization of bothcompact size and high capacitance at the same time in a chip capacitorcan be achieved further and a capacitor with which the capacitance valuecan be adjusted with high precision over a wide range can be provided.

However, in arranging a chip capacitor with a multilayer structure, caremust be taken to position the fuses of the respective electrode films soas not to overlap in a plan view as described above. Further, althoughwith each of the preferred embodiments, an example where each fuse unitis made integral with any one of the first electrode film 11, secondelectrode film 13, and third electrode film 16 was described, the fuseunits may be formed from a conductor film separate from the firstelectrode film 11, second electrode film 13, and third electrode film16. Further, although with each of the preferred embodiments, an examplewhere the plurality of capacitor elements include a plurality ofcapacitor elements having capacitance values that form a geometricprogression with a common ratio r (0<r; r≠1)=2 was described, the commonratio of the geometric progression may be a numeral other than 2. Alsowith each of the preferred embodiments, the insulating film 8 is formedon the top surface of the substrate 2, the insulating film 8 may beomitted if the substrate 2 is an insulating substrate. Also, aconductive substrate may be used as the substrate 2, the conductivesubstrate may be used as a lower electrode, and the first capacitancefilm 12 may be formed so as to be in contact with the top surface of theconductive substrate. In this case, one of the external electrodes maybe led out from a rear surface of the conductive substrate.

Besides the above, various design changes may be applied within thescope of the matters described in the claims. <Invention according to afirst reference example> (1) Features of the invention according to thefirst reference example. For example, the features of the inventionaccording to the first reference example are the following A1 to A20.(A1) A chip capacitor including a substrate, a first external electrodedisposed on the substrate, a second external electrode disposed on thesubstrate, a plurality of capacitor elements formed on the substrate andconnected between the first external electrode and the second externalelectrode, and a plurality of fuses that are formed on the substrate,are each interposed between the plurality of capacitor elements and thefirst external electrode or the second external electrode, and arecapable of disconnecting each of the plurality of capacitor elements.

With the invention according to A1, the plurality of capacitor elementsare connected between the first and second external electrodes disposedon the substrate. The plurality of fuses that are capable ofdisconnecting each of the plurality of capacitor elements are providedbetween the plurality of capacitor elements and the first or secondexternal electrodes. A plurality of types of capacitance values can thusbe accommodated easily and rapidly by selecting and cutting one or aplurality of the fuses. In other words, a common design can be appliedto chip capacitors of a plurality of types of capacitance values. (A2)The chip capacitor according to A1, where the plurality of capacitorelements have mutually different capacitance values.

With the invention according to A2, chip capacitors of variouscapacitance values can be realized with a common design by combining aplurality of the capacitor elements that differ in capacitance value.(A3) The chip capacitor according to A2, where the capacitance values ofthe plurality of capacitor elements are set to form a geometricprogression. By the invention according to A3, the capacitance value ofthe chip capacitor can be adjusted accurately to a desired capacitancevalue by appropriate selection of a plurality of the capacitor elementsto be connected between the first external electrode and the secondexternal electrode. For example, by setting the common ratio of thegeometric progression to 2, the capacitance value of the chip capacitorcan be adjusted at the precision of the first term of the geometricprogression (term of the smallest value in the geometric progression).(A4) The chip capacitor according to any one of A1 to A3, where at leastone of the plurality of fuses is cut.

With the chip capacitor that has been adjusted in capacitance value, oneor a plurality of the fuses may be cut. The capacitor elements to beconnected between the first external electrode and the second externalelectrode can be selected by fuse cutting and the chip capacitor of therequired capacitance value can thereby be realized. (A5) The chipcapacitor according to any one of A1 to A4, including a lower electrodefilm formed on the substrate, a capacitance film formed on the lowerelectrode film, and an upper electrode film formed on the capacitancefilm so as to face the lower electrode film, and where one electrodefilm among the upper electrode film and the lower electrode filmincludes a plurality of divided electrode film portions and theplurality of capacitor elements are formed by the plurality of theelectrode film portions facing the other electrode film, among the upperelectrode film and the lower electrode film, across the capacitancefilm.

With the invention according to A5, a capacitor structure is arranged bythe capacitance film being sandwiched between the lower electrode filmand the upper electrode film. One electrode film among the upperelectrode film and the lower electrode film is divided into theplurality of electrode film portions so that the respective electrodefilm portions face the other electrode film and the plurality ofcapacitor elements are thereby provided on the substrate. (A6) The chipcapacitor according to A5, where the plurality of electrode filmportions face the other electrode film over mutually different facingareas.

With the invention according to A6, the plurality of capacitor elementscorresponding to the plurality of electrode film portions that mutuallydiffer in facing area have mutually different capacitance values. Chipcapacitors of a plurality of types of capacitance values can thus berealized by appropriate combination of the capacitor elements. Morespecifically, when the fuses corresponding to the capacitor elementsother than the selected plurality of the capacitor elements are cut, thefuses are disconnected from between the first and second externalelectrodes. The disconnection enables the chip capacitor to have therequired capacitance value. (A7) The chip capacitor according to A6,where the facing areas of the plurality of electrode film portions areset to form a geometric progression.

By the invention according to A7, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting. (A8) Thechip capacitor according to any one of A5 to A7, where the plurality ofelectrode film portions and the fuses are formed of films of the sameconductive material.

By the invention according to A8, the electrode film portions and thefuses can be arranged from a conductive material film in common Eachelectrode film portion can be disconnected by cutting the fusecorresponding to the electrode film portion. (A9) The chip capacitoraccording to any one of A1 to A8, further including a protective filmformed to cover the upper electrode film and expose the first externalelectrode and the second external electrode.

By the invention according to A9, the upper electrode film can becovered by the protective film while exposing the first and secondexternal electrodes, thereby enabling a chip capacitor that is capableof realizing a plurality of types of capacitance values with a commondesign and is high in reliability to be provided. (A10) The chipcapacitor according to A9, where the protective film extends to a sidesurface of the substrate and covers the side surface.

With the invention according to A10, protection is also provided fromthe side surface of the substrate, thereby enabling further improvementof the reliability of the chip capacitor. (A11) A method formanufacturing a chip capacitor including a first external electrode anda second external electrode, the method including a step of forming aplurality of capacitor elements on a substrate, a step of forming, onthe substrate, a plurality of fuses that disconnectably connect each ofthe plurality of capacitor elements to the first external electrode orthe second external electrode, and a step of forming the first externalelectrode and the second external electrode on the substrate.

By the invention according to A11, chip capacitors being of a commondesign and yet being of a plurality of capacitance values can bemanufactured by cutting the fuses that are selected in accordance withthe required capacitance values. (A12) The method for manufacturing achip capacitor according to A11, where the plurality of capacitorelements are formed to have mutually different capacitance values.

By the invention according to A12, a plurality of types of capacitancevalues can be realized by appropriately selecting and combining aplurality of the capacitor elements. (A13) The method for manufacturinga chip capacitor according to A12, where the capacitance values of theplurality of capacitor elements are set to form a geometric progression.With the invention according to A13, a plurality of types of capacitancevalues can be realized and fine adjustment with respect to (adjustmentto) a desired capacitance value is made possible by appropriatelyselecting and combining a plurality of the capacitor elements. Forexample, by setting the common ratio of the geometric progression to 2,the capacitance value of the chip capacitor can be adjusted at theprecision of the first term of the geometric progression (term of thesmallest value in the geometric progression). (A14) The method formanufacturing a chip capacitor according to any one of A11 to A13,further including a step of cutting at least one of the plurality offuses.

By the invention according to A14, the capacitance value of the chipcapacitor can be adjusted to the desired capacitance value byappropriately selecting each fuse to be cut. That is, the chip capacitoradjusted to the desired capacitance value can be manufactured byappropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected. (A15) The method formanufacturing a chip capacitor according to A14, further including astep of measuring a total capacitance value of the plurality ofcapacitor elements and a step of selecting each fuse to be cut based onthe measured total capacitance value, and where each selected fuse iscut in the fuse cutting step.

By the invention according to A15, the total capacitance value of theplurality of capacitor elements is measured, each fuse to be cut isselected based on the measurement result, and therefore the capacitancevalue of the chip capacitor can be set to the targeted capacitance valuereliably. (A16) The method for manufacturing a chip capacitor accordingto A14 or A15, further including a step of forming, after cutting thefuse or fuses, a protective film covering the cut portion of each fuse.

By the invention according to A16, the cut portion of each fuse iscovered by the protective film and therefore entry of foreign matter andmoisture with respect to the cut portion can be avoided to enable a chipcapacitor, which can realize a plurality of types of capacitance valueswith a common design and is high in reliability, to be manufactured.(A17) The method for manufacturing a chip capacitor according to any oneof A11 to A16, where the step of forming the plurality of capacitorelements includes a step of forming a lower electrode film on thesubstrate, a step of forming a capacitance film on the lower electrodefilm, a step of forming an upper electrode film on the capacitance filmso as to face the lower electrode film, and a step of dividing (forexample, dividing by photolithography) one electrode film among theupper electrode film and the lower electrode film into a plurality ofelectrode film portions, and the plurality of capacitor elements areformed by the plurality of electrode film portions facing the otherelectrode film, among the upper electrode film and the lower electrodefilm, across the capacitance film.

By the invention according to A17, a capacitor structure having thecapacitance film sandwiched between the lower electrode film and theupper electrode film can be formed. By one electrode film among theupper electrode film and the lower electrode film being divided into theplurality of electrode film portions, the plurality of capacitorelements, having the structure where the capacitance film is sandwichedbetween the divided electrode film portions and the other electrodefilm, can be formed on the substrate. (A18) The method for manufacturinga chip capacitor according to A17, where the one electrode film isdivided so that the plurality of electrode film portions face the otherelectrode film over mutually different facing areas.

By the invention according to A18, the plurality of capacitor elementsof different capacitance values can be formed on the substrate by makingthe plurality of electrode film portions face the other electrode filmover mutually different facing areas. Chip capacitors of a plurality oftypes of capacitance values can thus be manufactured by appropriateselection and combination of the capacitor elements of differentcapacitance values. (A19) The method for manufacturing a chip capacitoraccording to A18, where the facing areas of the plurality of electrodefilm portions are set to form a geometric progression.

By the invention according to A19, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be formed on the substrate. Chip capacitors of a plurality of typesof capacitance values can thereby be provided and accurate adjustment tothe desired capacitance value can be performed by appropriate selectionand combination of a plurality of the capacitor elements. (A20) Themethod for manufacturing a chip capacitor according to any one of A17 toA19, where the one electrode film and the fuses are formed of films ofthe same conductive material.

By the invention according to A20, the electrode film portions and thefuses can be formed of films of the same conductive material and canthus be formed by patterning from the same film. The manufacturingprocess is thereby simplified. (2) Preferred embodiments of theinvention according to the first reference example Preferred embodimentsof the first reference example shall now be described in detail withreference to the attached drawings.

FIG. 10 is a plan view of a chip capacitor according to a firstpreferred embodiment of the first reference example, and FIG. 11 is asectional view thereof showing a section taken along section line XI-XIin FIG. 10. Further, FIG. 12 is an exploded perspective view showing thearrangement of a portion of the chip capacitor in a separated state. Thechip capacitor 31 includes a substrate 32, a first external electrode 33disposed on the substrate 32, and a second external electrode 34disposed similarly on the substrate 32. In the present preferredembodiment, the substrate 32 has, in a plan view, a rectangular shapewith the four corners chamfered. The first external electrode 33 and thesecond external electrode 34 are respectively disposed at portions atrespective ends in the long direction of the substrate 32. In thepresent preferred embodiment, each of the first external electrode 33and the second external electrode 34 has a substantially rectangularplanar shape extending in the short direction of the substrate 32 andhas chamfered portions at two locations respectively corresponding tothe corners of the substrate 32. On the substrate 32, a plurality ofcapacitor elements C1 to C9 are disposed within a capacitor arrangementregion 35 between the first external electrode 33 and the secondexternal electrode 34. The plurality of capacitor elements C1 to C9 areelectrically connected respectively to the first external electrode 33via a plurality of fuse units 37.

As shown in FIG. 11 and FIG. 12, an insulating film 38 is formed on thetop surface of the substrate 32, and a lower electrode film 41 is formedon the top surface of the insulating film 38. The lower electrode film41 is formed to spread across substantially the entirety of thecapacitor arrangement region 35 and extend to a region directly belowthe second external electrode 34. More specifically, the lower electrodefilm 41 has a capacitor electrode region 41A functioning as a lowerelectrode in common to the capacitor elements C1 to C9 and a pad region41B for leading out to an external electrode. The capacitor electroderegion 41A is positioned in the capacitor arrangement region 35 and thepad region 41B is positioned directly below the second externalelectrode 34.

In the capacitor arrangement region 35, a capacitance film (dielectricfilm) 42 is formed so as to cover the lower electrode film 41 (capacitorelectrode region 41A). The capacitance film 42 is continuous across theentirety of the capacitor electrode region 41A and, in the presentpreferred embodiment, further extends to a region directly below thefirst external electrode 33 and covers the insulating film 38 outsidethe capacitor arrangement region 35. An upper electrode film 43 isformed on the capacitance film 42. In FIG. 10, the upper electrode film43 is colored for the sake of clarity. The upper electrode film 43includes a capacitor electrode region 43A positioned in the capacitorarrangement region 35, a pad region 43B positioned directly below thefirst external electrode 33, and a fuse region 43C disposed between thepad region 43B and the capacitor electrode region 43A.

In the capacitor electrode region 43A, the upper electrode film 43 isdivided into a plurality of electrode film portions 231 to 239. In thepresent preferred embodiment, the respective electrode film portions 231to 239 are all formed to rectangular shapes and extend in the form ofbands from the fuse region 43C toward the second external electrode 34.The plurality of electrode film portions 231 to 239 face the lowerelectrode film 41 across the capacitance film 42 over a plurality oftypes of facing areas. More specifically, a ratio of the facing areas ofthe electrode film portions 231 to 239 with respect to the lowerelectrode film 41 may be set to be 1:2:4:8:16:32:64:128:128. That is,the plurality of electrode film portions 231 to 239 include theplurality of electrode film portions differing in facing area and morespecifically include the plurality of electrode film portions 231 to 238(or 231 to 237 and 239) having facing areas that are set to form ageometric progression with a common ratio of 2. The plurality ofcapacitor elements C1 to C9, respectively arranged by the respectiveelectrode film portions 231 to 239 and the facing lower electrode film41 across the capacitance film 42, thus include the plurality ofcapacitor elements having mutually different capacitance values. If theratio of the facing areas of the electrode film portions 231 to 239 isas mentioned above, the ratio of the capacitance values of the capacitorelements C1 to C9 is equal to the ratio of the facing areas and is1:2:4:8:16:32:64:128:128. The plurality of capacitor elements C1 to C9thus include the plurality of capacitor elements C1 to C8 (or C1 to C7and C9) with capacitance values set to form the geometric progressionwith the common ratio of 2.

In the present preferred embodiment, the electrode film portions 231 to235 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4:8:16. Also, the electrode filmportions 235, 236, 237, 238, and 239 are formed to bands that are equalin length and have widths with the ratio thereof being set to 1:2:4:8:8.The electrode film portions 235 to 239 are formed to extend across arange from an end edge at the first external electrode 33 side to an endedge at the second external electrode 34 side of the capacitorarrangement region 35, and the electrode film portions 231 to 234 areformed to be shorter than this range.

The pad region 43B is formed to be substantially similar in shape to thefirst external electrode 33 and has a substantially rectangular planarshape having two chamfered portions corresponding to corner portions ofthe substrate 32. The fuse region 43C is disposed along one long side(the long side at the inner side with respect to the peripheral edge ofthe substrate 32) of the pad region 43B. The fuse region 43C includesthe plurality of fuse units 37 that are aligned along the one long sideof the pad region 43B. The fuse units 37 are formed of the same materialas and to be integral to the pad region 43B of the upper electrode film43. The plurality of electrode film portions 231 to 239 are each formedintegral to one or a plurality of the fuse units 37, are connected tothe pad region 43B via the fuse units 37, and are electrically connectedto the first external electrode 33 via the pad region 43B. Each of theelectrode film portions 231 to 236 of comparatively small area isconnected to the pad region 43B via a single fuse unit 37, and each ofthe electrode film portions 237 to 239 of comparatively large area isconnected to the pad region 43B via a plurality of fuse units 37. It isnot necessary for all of the fuse units 37 to be used and, in thepresent preferred embodiment, a portion of the fuse units 37 is unused.

The fuse units 37 include first wide portions 37A arranged to beconnected to the pad region 43B, second wide portions 37B arranged to beconnected to the electrode film portions 231 to 239, and narrow portions37C connecting the first and second wide portions 37A and 37B. Thenarrow portions 37C are arranged to be capable of being cut (fused) bylaser light. Unnecessary electrode film portions among the electrodefilm portions 231 to 239 can thus be electrically disconnected from thefirst and second external electrodes 33 and 34 by cutting the fuse units37.

Although omitted from illustration in FIG. 10 and FIG. 12, the topsurface of the chip capacitor 31 that includes the top surface of theupper electrode film 43 is covered by a passivation film 39 as shown inFIG. 11. The passivation film 39 is constituted, for example, of anitride film and is formed not only to cover the upper surface of thechip capacitor 31 but also to extend to side surfaces of the substrate32 and cover the side surfaces. Further, a resin film 40, made of apolyimide resin, etc., is formed on the passivation film 39. The resinfilm 40 is formed to cover the upper surface of the chip capacitor 31and extend to the side surfaces of the substrate 32 to cover thepassivation film 39 on the side surfaces.

The passivation film 39 and the resin film 40 are protective films thatprotect the top surface of the chip capacitor 31. In these films, padopenings 44 and 45 are respectively formed in regions corresponding tothe first external electrode 33 and the second external electrode 34.The pad openings 44 and 45 penetrate through the passivation film 39 andthe resin film 40 so as to respectively expose a region of a portion ofthe pad region 43B of the upper electrode film 43 and a region of aportion of the pad region 41B of the lower electrode film 41. Further,with the present preferred embodiment, the pad opening 45 correspondingto the second external electrode 34 also penetrates through thecapacitance film 42.

The first external electrode 33 and the second external electrode 34 arerespectively embedded in the pad openings 44 and 45. The first externalelectrode 33 is thereby bonded to the pad region 43B of the upperelectrode film 43 and the second external electrode 34 is bonded to thepad region 41B of the lower electrode film 41. The first and secondexternal electrodes 33 and 34 are formed to project from the top surfaceof the resin film 40. The chip capacitor 31 can thereby be flip-chipbonded to a mounting substrate.

FIG. 13 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor 31. The plurality of capacitor elementsC1 to C9 are connected in parallel between the first external electrode33 and the second external electrode 34. Fuses F1 to F9, each arrangedfrom one or a plurality of the fuse units 37, are interposed in seriesbetween the respective capacitor elements C1 to C9 and the firstexternal electrode 33. When all of the fuses F1 to F9 are connected, thecapacitance value of the chip capacitor 31 is equal to the total of thecapacitance values of the capacitor elements C1 to C9. When one or twoor more fuses selected from among the plurality of fuses F1 to F9 is orare cut, each capacitor element corresponding to a cut fuse isdisconnected and the capacitance value of the chip capacitor 31decreases by just the capacitance value of the disconnected capacitorelement or elements.

Therefore by measuring the capacitance value across the pad regions 41Band 43B (the total capacitance value of the capacitor elements C1 to C9)and thereafter using laser light to fuse one or a plurality of fusesselected appropriately from among the fuses F1 to F9 in accordance witha desired capacitance value, adjustment (laser trimming) to the desiredcapacitance value can be performed. In particular, if the capacitancevalues of the capacitor elements C1 to C8 are set to form a geometricprogression with a common ratio of 2, fine adjustment to the targetedcapacitance value at a precision corresponding to the capacitance valueof the capacitor element C1, which is the smallest capacitance value(value of the first term in the geometric progression), is madepossible.

For example, the capacitance values of the capacitor elements C1 to C9may be set as follows. C1=0.03125 pF C2=0.0625 pF C3=0.125 pF C4=0.25 pFC5=0.5 pF C6=1 pF C7=2 pF C8=4 pF C9=4 pF. In this case, the capacitanceof the chip capacitor 31 can be finely adjusted at a minimum adjustmentprecision of 0.03125 pF. Also, the fuses to be cut among the fuses F1 toF9 can be selected appropriately to provide the chip capacitor 31 withan arbitrary capacitance value between 0.1 pF and 10 pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C9 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 33 and thesecond external electrode 34. The capacitor elements C1 to C9 include aplurality of capacitor elements that differ in capacitance value andmore specifically include a plurality of capacitor elements withcapacitance values set to form a geometric progression. The chipcapacitor 31, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Details of respective portions of the chip capacitor 31 shall now bedescribed. The substrate 32 may have, for example, a rectangular shapeof 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2 mm×0.1 mm, etc. (preferably asize of not more than 0.4 mm×0.2 mm) in a plan view. The capacitorarrangement region 35 is generally a square region with each side havinga length corresponding to the length of the short side of the substrate32. The thickness of the substrate 32 may be approximately 150 μm. Thesubstrate 32 may, for example, be a substrate that has been thinned bygrinding or polishing from a rear surface side (surface on which thecapacitor elements C1 to C9 are not formed). As the material of thesubstrate 32, a semiconductor substrate as represented by a siliconsubstrate may be used or a glass substrate may be used or a resin filmmay be used.

The insulating film 38 may be a silicon oxide film or other oxide film.The film thickness thereof may be approximately 500 Å to 2000 Å. Thelower electrode film 41 is preferably a conductive film, a metal film inparticular, and may, for example, be an aluminum film. The lowerelectrode film 41 that is constituted of an aluminum film may be formedby a sputtering method. Similarly, the upper electrode film 43 ispreferably constituted of a conductive film, a metal film in particular,and may, for example, be an aluminum film. The upper electrode film 43that is constituted of an aluminum film may be formed by the sputteringmethod. The patterning for dividing the capacitor electrode region 43Aof the upper electrode film 43 into the electrode film portions 231 to239 and shaping the fuse region 43C into the plurality of fuse units 37may be performed by photolithography and etching processes.

The capacitance film 42 may be constituted, for example, of a siliconnitride film, and the film thickness thereof may be 500 Å to 2000 Å (forexample, 1000 Å). The capacitance film 42 may be a silicon nitride filmformed by plasma CVD (chemical vapor deposition). The passivation film39 may be constituted, for example, of a silicon nitride film and may beformed, for example, by the plasma CVD method. The film thicknessthereof may be approximately 8000 Å. As mentioned above, the resin film40 may be constituted of a polyimide film or other resin film.

Each of the first and second external electrodes 33 and 34 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the lower electrode film 41 or the upper electrodefilm 43, a palladium layer laminated on the nickel layer, and a goldlayer laminated on the palladium layer are laminated, and may be formed,for example, by a plating method (or more specifically, an electrolessplating method). The nickel layer contributes to improvement of adhesionwith the lower electrode film 41 or the upper electrode film 43, and thepalladium layer functions as a diffusion preventing layer thatsuppresses mutual diffusion of the material of the upper electrode filmor the lower electrode film and the gold of the uppermost layer of eachof the first and second external electrodes 33 and 34.

FIG. 14 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 31. The insulating film 38, constitutedof an oxide film (for example, a silicon oxide film), is formed on thetop surface of the substrate 32 by a thermal oxidation method and/or CVDmethod (step S1). Thereafter, the lower electrode film 41, constitutedof an aluminum film, is formed over the entire top surface of theinsulating film 38, for example, by the sputtering method (step S2). Thefilm thickness of the lower electrode film 41 may be approximately 8000Å. Thereafter, a resist pattern corresponding to the final shape of thelower electrode film 41 is formed on the top surface of the lowerelectrode film by photolithography (step S3). The lower electrode film41 is etched using the resist pattern as a mask to obtain the lowerelectrode film 41 of the pattern shown in FIG. 10, etc. (step S4). Theetching of the lower electrode film 41 may be performed, for example, byreactive ion etching.

Thereafter, the capacitance film 42, constituted of a silicon nitridefilm, etc., is formed on the lower electrode film 41, for example, bythe plasma CVD method (step S5). In the region in which the lowerelectrode film 41 is not formed, the capacitance film 42 is formed onthe top surface of the insulating film 38. Thereafter, the upperelectrode film 43 is formed on the capacitance film 42 (step S6). Theupper electrode film 43 is constituted, for example, of an aluminum filmand may be formed by the sputtering method. The film thickness thereofmay be approximately 8000 Å. Thereafter, a resist pattern correspondingto the final shape of the upper electrode film 43 is formed on the topsurface of the upper electrode film 43 by photolithography (step S7).The upper electrode film 43 is patterned to its final shape (see FIG.10, etc.) by etching using the resist pattern as a mask (step S8). Theupper electrode film 43 is thereby shaped to the pattern having theplurality of electrode film portions 231 to 239 in the capacitorelectrode region 43A, having the plurality of fuse units 37 in the fuseregion 43C, and having the pad region 43B connected to the fuse units37. The etching for patterning the upper electrode film 43 may beperformed by wet etching using an etching liquid, such as phosphoricacid, etc., or may be performed by reactive ion etching.

Thereafter, inspection probes are contacted against the pad region 43Bof the upper electrode film 43 and the pad region 41B of the lowerelectrode film 41 to measure the total capacitance value of theplurality of capacitor elements C1 to C9 (step S9). Based on themeasured total capacitance value, the capacitor elements to bedisconnected, that is, the fuses to be cut are selected in accordancewith the targeted capacitance value of the chip capacitor 31 (step S10).

Thereafter as shown in FIG. 15A, a cover film 46, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 32 (step S11). The forming of the cover film 46 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 46 covers the patterned upper electrode film 43 and coversthe capacitance film 42 in the region in which the upper electrode film43 is not formed. The cover film 46 covers the fuse units 37 in the fuseregion 43C.

From this state, the laser trimming for fusing the fuse units 37 isperformed (step S12). That is, as shown in FIG. 15B, each fuse unit 37constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 47 and thenarrow portion 37C of the fuse unit 37 is fused. The correspondingcapacitor element is thereby disconnected from the pad region 43B. Whenthe laser light 47 is irradiated on the fuse unit 37, the energy of thelaser light 47 is accumulated at a vicinity of the fuse unit 37 by theaction of the cover film 46 and the fuse unit 37 is thereby fused.

Thereafter as shown in FIG. 15C, a silicon nitride film is deposited onthe cover film 46, for example, by the plasma CVD method to form thepassivation film 39 (step S13). In the final form, the cover film 46 ismade integral with the passivation film 39 to constitute a portion ofthe passivation film 39. The passivation film 39 that is formed afterthe cutting of the fuses enters into openings in the cover film 46,destroyed at the same time as the fusing of the fuses, to protect thecut surfaces of the fuse units 37. The passivation film 39 thus preventsentry of foreign matter and entry of moisture into the cut locations ofthe fuse units 37. The passivation film 39 may be formed to have a filmthickness, for example, of approximately 8000 Å as a whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 33 and 34 are to beformed, is formed on the passivation film 39 (step S14). The passivationfilm 39 is etched using the resist pattern as a mask. The pad openingexposing the lower electrode film 41 in the pad region 41B and the padopening exposing the upper electrode film 43 in the pad region 43B arethereby formed (step S15). The etching of the passivation film 39 may beperformed by reactive ion etching. In the process of etching of thepassivation film 39, the capacitance film 42, which is similarlyconstituted of a nitride film, is also opened and the pad region 41B ofthe lower electrode film 41 is thereby exposed.

Thereafter a resin film is coated on the entire surface (step S16). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S17). The pad openings 44 and 45 penetrating through the resinfilm 40 and the passivation film 39 are thereby formed. Thereafter, heattreatment (curing) for hardening the resin film is performed (step S18)and further, the first external electrode 33 and the second externalelectrode 34 are grown inside the pad openings 44 and 45, for example,by the electroless plating method (step S19). The chip capacitor 31 ofthe structure shown in FIG. 10, etc., is thereby obtained.

In the patterning of the upper electrode film 43 using thephotolithography process, the electrode film portions 231 to 239 ofminute areas can be formed with high precision and the fuse units 37 ofeven finer pattern can be formed. After the patterning of the upperelectrode film 43, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 31 that is accurately adjusted to the desired capacitancevalue can be obtained.

FIG. 16 is a plan view for describing the arrangement of a chipcapacitor 48 according to a second preferred embodiment of the firstreference example. In FIG. 16, portions corresponding to respectiveportions shown in FIG. 10 are indicated using the same reference symbolsas in FIG. 10. In the first preferred embodiment, the capacitorelectrode region 43A of the upper electrode film 43 is divided into theelectrode film portions 231 to 239 each having a band shape. In thiscase, regions that cannot be used as capacitor elements are formedwithin the capacitor arrangement region 35 as shown in FIG. 10 andeffective use cannot be made of the restricted region on the smallsubstrate 32.

Therefore with the preferred embodiment shown in FIG. 16, the pluralityof electrode film portions 231 to 239 are divided into L-shapedelectrode film portions 241 to 249. For example, the electrode filmportion 249 in the arrangement of FIG. 16 can thereby be made to facethe lower electrode film 41 over an area that is 1.5 times that of theelectrode film portion 239 in the arrangement of FIG. 10. Therefore, ifthe capacitor element C9 corresponding to the electrode film portion 239in the first preferred embodiment of FIG. 10 has a capacitance of 4 pF,the capacitor element C9 can be made to have a capacitance of 6 pF byuse of the electrode film portion 249 of the present preferredembodiment. The capacitance value of the chip capacitor 48 can therebybe set over a wider range by making effective use of the interior of thecapacitor arrangement region 35.

The process for manufacturing the chip capacitor 48 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 14. However, in the patterning of the upper electrode film43 (steps S7 and S8), the capacitor electrode region 43A is divided intothe plurality of electrode film portions 241 to 249 of the shapes shownin FIG. 16. FIG. 17 is an exploded perspective view for describing thearrangement of a chip capacitor 49 according to a third preferredembodiment of the first reference example, and the respective portionsof the chip capacitor 49 are shown in the same manner as in FIG. 12 usedfor describing the first preferred embodiment.

With the first preferred embodiment, the lower electrode film 41 has thecapacitor electrode region 41A constituted of a pattern that iscontinuous across substantially the entirety of the capacitorarrangement region 35, and the capacitor electrode region 43A of theupper electrode film 43 is divided into the plurality of electrode filmportions 231 to 239. In contrast, with the present preferred embodiment,whereas the capacitor electrode region 43A of the upper electrode film43 is formed to a continuous film pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 35, thecapacitor electrode region 41A of the lower electrode film 41 is dividedinto a plurality of electrode film portions 251 to 259. The electrodefilm portions 251 to 259 may be formed in the same shapes and area ratioas those of the electrode film portions 231 to 239 in the firstpreferred embodiment or may be formed in the same shapes and area ratioas those of the electrode film portions 241 to 249 in the secondpreferred embodiment. A plurality of capacitor elements are thusarranged by the electrode film portions 251 to 259, the capacitance film42, and the upper electrode film 43. At least a portion of the pluralityof capacitor elements constitutes a set of capacitor elements thatdiffer in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression).

The lower electrode film 41 further has a fuse region 41C between thecapacitor electrode region 41A and the pad region 41B. In the fuseregion 41C, a plurality of fuse units 50, similar to the fuse units 37of the first preferred embodiment, are aligned in a single column alongthe pad region 41B. Each of the electrode film portions 251 to 259 isconnected to the pad region 41B via one or a plurality of the fuse units50.

The electrode film portions 251 to 259 face the upper electrode film 43over mutually different facing areas in the present arrangement as welland any of these can be disconnected individually by cutting the fuseunit 50. The same effects as those of the first preferred embodiment arethus obtained. In particular, by forming at least a portion of theplurality of electrode film portions 251 to 259 so as to face the upperelectrode film 43 over facing areas set to form a geometric progressionwith a common ratio of 2, a chip capacitor that is precisely adjusted tothe required capacitance value can be provided in the same manner as inthe first preferred embodiment.

The process for manufacturing the chip capacitor 49 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 14. However, in the patterning of the lower electrode film41 (steps S3 and S4), the capacitor electrode region 41A is divided intothe electrode film portions 251 to 259 and the plurality of fuse units50 are formed in the fuse region 41C. Also, in the patterning of theupper electrode film 43 (steps S7 and S8), a plurality of electrode filmportions are not formed and fuse units are also not formed. Further, inthe laser trimming (step S12), the fuse units 50 formed in the lowerelectrode film 41 are cut by laser light. The lower electrode film 41 iscovered by the capacitance film 42 and the capacitance film 42 can thusbe used as a cover film for accumulating the energy of the laser lightin the process of laser trimming. The forming of the cover film (stepS11) immediately before the laser trimming may thus be omitted.

Although preferred embodiments of the first reference example have beendescribed above, the first reference example may be implemented in yetother modes as well. For example, although with each of the preferredembodiments described above, the arrangement where just one of either ofthe upper electrode film and the lower electrode film is divided intothe plurality of electrode films was described, both the upper electrodefilm and the lower electrode film may be divided into a plurality ofelectrode film portions. Further, although with each of the preferredembodiments, an example where each fuse unit is made integral with theupper electrode film or the lower electrode film was described, the fuseunits may be formed from a conductor film separate from the upperelectrode film and the lower electrode film. Further, although with eachof the preferred embodiments, an example where the plurality ofcapacitor elements include a plurality of capacitor elements havingcapacitance values that form a geometric progression with a common ratior (0<r; r≠1)=2 was described, the common ratio of the geometricprogression may be a numeral other than 2. Also with each of thepreferred embodiments, the insulating film 38 is formed on the topsurface of the substrate 32, the insulating film 38 may be omitted ifthe substrate 32 is an insulating substrate. Also, a conductivesubstrate may be used as the substrate 32, the conductive substrate maybe used as a lower electrode, and the capacitance film 42 may be formedso as to be in contact with the top surface of the conductive substrate.In this case, one of the external electrodes may be led out from a rearsurface of the conductive substrate.

Besides the above, various design changes may be applied within thescope of the matters described as features of the invention according tothe (1) first reference example. For example, arrangements with which astep of manufacture not specified in the respective features A1 to A20is changed, omitted, or added are also included within the scope of thefirst reference example. <Invention according to a second referenceexample> (1) Features of the invention according to the second referenceexample. For example, the features of the invention according to thesecond reference example are the following B1 to B25. (B1) A chipcapacitor including a substrate, a first external electrode disposed onthe substrate, a second external electrode disposed on the substrate, aplurality of capacitor elements formed on the substrate and connectedbetween the first external electrode and the second external electrode,a plurality of fuses that are formed on the substrate, are eachinterposed between the plurality of capacitor elements and the firstexternal electrode or the second external electrode, and are capable ofdisconnecting each of the plurality of capacitor elements, and a pair ofdiodes formed inside the substrate and connected in mutually oppositedirections between a region including a portion directly below the firstexternal electrode and a region including a portion directly below thesecond external electrode.

With the invention according to B1, the plurality of capacitor elementsare connected between the first and second external electrodes disposedon the substrate. The plurality of fuses that are capable ofdisconnecting each of the plurality of capacitor elements are providedbetween the plurality of capacitor elements and the first or secondexternal electrodes. A plurality of types of capacitance values can thusbe accommodated easily and rapidly by selecting and cutting one or aplurality of the fuses. In other words, a common design can be appliedto chip capacitors of a plurality of types of capacitance values. Also,the chip capacitor can be adjusted in capacitance value accuratelywithout being influenced by parasitic capacitance. (B2) The chipcapacitor according to B1, where the pair of diodes include an impuritydiffusion region, formed in a top surface region of the substrateincluding the portion directly below the first external electrode or aportion directly below the lower electrode, and an impurity diffusionregion, formed in a top surface region of the substrate including theportion directly below the second external electrode or a portiondirectly below the lower electrode.

By the invention according to B2, the pair of diodes can be formedeasily by forming the impurity diffusion regions. (B3) The chipcapacitor according to B2, where the substrate is a semiconductorsubstrate and the pair of diodes are formed by pn junctions of thesubstrate and the impurity regions. By the invention according to B3,the pair of diodes can be prepared readily using the pn junctions of thesemiconductors. (B4) The chip capacitor according to any one of B1 toB3, where the plurality of capacitor elements have mutually differentcapacitance values.

With the invention according to B4, chip capacitors of variouscapacitance values can be realized with a common design by combining aplurality of the capacitor elements that differ in capacitance value.(B5) The chip capacitor according to B4, where the capacitance values ofthe plurality of capacitor elements are set to form a geometricprogression. By the invention according to B5, the capacitance value ofthe chip capacitor can be adjusted accurately to a desired capacitancevalue by appropriate selection of a plurality of the capacitor elementsto be connected between the first external electrode and the secondexternal electrode. For example, by setting the common ratio of thegeometric progression to 2, the capacitance value of the chip capacitorcan be adjusted at the precision of the first term of the geometricprogression (term of the smallest value in the geometric progression).(B6) The chip capacitor according to any one of B1 to B5, where at leastone of the plurality of fuses is cut.

With the invention according to B6, one or a plurality of the fuses maybe cut in the chip capacitor that has been adjusted in capacitancevalue. The capacitor elements to be connected between the first externalelectrode and the second external electrode can be selected by fusecutting and the chip capacitor of the required capacitance value canthereby be realized. (B7) The chip capacitor according to any one of B1to B6, including a lower electrode film formed on the substrate, acapacitance film formed on the lower electrode film, and an upperelectrode film formed on the capacitance film so as to face the lowerelectrode film, and where one electrode film among the upper electrodefilm and the lower electrode film includes a plurality of dividedelectrode film portions and the plurality of capacitor elements areformed by the plurality of the electrode film portions facing the otherelectrode film, among the upper electrode film and the lower electrodefilm, across the capacitance film.

With the invention according to B7, a capacitor structure is arranged bythe capacitance film being sandwiched between the lower electrode filmand the upper electrode film. One electrode film among the upperelectrode film and the lower electrode film is divided into theplurality of electrode film portions so that the respective electrodefilm portions face the other electrode film and the plurality ofcapacitor elements are thereby provided on the substrate. (B8) The chipcapacitor according to B7, where the plurality of electrode filmportions face the other electrode film over mutually different facingareas.

With the invention according to B8, the plurality of capacitor elementscorresponding to the plurality of electrode film portions that mutuallydiffer in facing area have mutually different capacitance values. Chipcapacitors of a plurality of types of capacitance values can thus berealized by appropriate combination of the capacitor elements. Morespecifically, when the fuses corresponding to the capacitor elementsother than the selected plurality of the capacitor elements are cut, thefuses are disconnected from between the first and second externalelectrodes. The disconnection enables the chip capacitor to have therequired capacitance value. (B9) The chip capacitor according to B8,where the facing areas of the plurality of electrode film portions areset to form a geometric progression.

By the invention according to B9, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting. (B10)The chip capacitor according to any one of B7 to B9, where the pluralityof electrode film portions and the fuses are formed of films of the sameconductive material.

By the invention according to B10, the electrode film portions and thefuses can be arranged from a conductive material film in common Eachelectrode film portion can be disconnected by cutting the fusecorresponding to the electrode film portion. (B11) The chip capacitoraccording to any one of B1 to B10, further including a protective filmformed to cover the upper electrode film and expose the first externalelectrode and the second external electrode.

By the invention according to B11, the upper electrode film can becovered by the protective film while exposing the first and secondexternal electrodes, thereby enabling a chip capacitor that is capableof realizing a plurality of types of capacitance values with a commondesign and is high in reliability to be provided. (B12) The chipcapacitor according to B11, where the protective film extends to a sidesurface of the substrate and covers the side surface.

With the invention according to B12, protection is also provided fromthe side surface of the substrate, thereby enabling further improvementof the reliability of the chip capacitor. (B13) A method formanufacturing a chip capacitor including a first external electrode anda second external electrode, the method including a step of forming adiffusion region in each of regions of the top surface region of thesubstrate respectively directly below the first external electrode andthe second external electrode, a step of forming a plurality ofcapacitor elements on a substrate, a step of forming, on the substrate,a plurality of fuses that disconnectably connect each of the pluralityof capacitor elements to the first external electrode or the secondexternal electrode, and a step of forming the first external electrodeand the second external electrode on the substrate.

By the invention according to B13, chip capacitors being of a commondesign and yet being of a plurality of capacitance values can bemanufactured by cutting the fuses that are selected in accordance withthe required capacitance values. Chip capacitors that are not influencedby parasitic capacitance can also be manufactured. (B14) The method formanufacturing a chip capacitor according to B13, where the plurality ofcapacitor elements are formed to have mutually different capacitancevalues.

By the invention according to B14, a plurality of types of capacitancevalues can be realized by appropriately selecting and combining aplurality of the capacitor elements. (B15) The method for manufacturinga chip capacitor according to B14, where the capacitance values of theplurality of capacitor elements are set to form a geometric progression.With the invention according to B15, a plurality of types of capacitancevalues can be realized and fine adjustment with respect to (adjustmentto) a desired capacitance value is made possible by appropriatelyselecting and combining a plurality of the capacitor elements. Forexample, by setting the common ratio of the geometric progression to 2,the capacitance value of the chip capacitor can be adjusted at theprecision of the first term of the geometric progression (term of thesmallest value in the geometric progression). (B16) The method formanufacturing a chip capacitor according to any one of B13 to B15,further including a step of cutting at least one of the plurality offuses.

By the invention according to B16, the capacitance value of the chipcapacitor can be adjusted to the desired capacitance value byappropriately selecting each fuse to be cut. That is, the chip capacitoradjusted to the desired capacitance value can be manufactured byappropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected. (B17) The method formanufacturing a chip capacitor according to B16, further including astep of measuring a total capacitance value of the plurality ofcapacitor elements and a step of selecting each fuse to be cut based onthe measured total capacitance value, and where each selected fuse iscut in the fuse cutting step.

By the invention according to B17, the total capacitance value of theplurality of capacitor elements is measured, each fuse to be cut isselected based on the measurement result, and therefore the capacitancevalue of the chip capacitor can be set to the targeted capacitance valuereliably. (B18) The method for manufacturing a chip capacitor accordingto B16 or B17, further including a step of forming, after cutting thefuse or fuses, a protective film covering the cut portion of each fuse.

By the invention according to B18, the cut portion of each fuse iscovered by the protective film and therefore entry of foreign matter andmoisture with respect to the cut portion can be avoided to enable a chipcapacitor, which can realize a plurality of types of capacitance valueswith a common design and is high in reliability, to be manufactured.(B19) The method for manufacturing a chip capacitor according to any oneof B13 to B18, where the step of forming the plurality of capacitorelements includes a step of forming a lower electrode film on thesubstrate, a step of forming a capacitance film on the lower electrodefilm, a step of forming an upper electrode film on the capacitance filmso as to face the lower electrode film, and a step of dividing (forexample, dividing by photolithography) one electrode film among theupper electrode film and the lower electrode film into a plurality ofelectrode film portions, and the plurality of capacitor elements areformed by the plurality of electrode film portions facing the otherelectrode film, among the upper electrode film and the lower electrodefilm, across the capacitance film.

By the invention according to B19, a capacitor structure having thecapacitance film sandwiched between the lower electrode film and theupper electrode film can be formed. By one electrode film among theupper electrode film and the lower electrode film being divided into theplurality of electrode film portions, the plurality of capacitorelements, having the structure where the capacitance film is sandwichedbetween the divided electrode film portions and the other electrodefilm, can be formed on the substrate. (B20) The method for manufacturinga chip capacitor according to B19, where the one electrode film isdivided so that the plurality of electrode film portions face the otherelectrode film over mutually different facing areas.

By the invention according to B20, the plurality of capacitor elementsof different capacitance values can be formed on the substrate by makingthe plurality of electrode film portions face the other electrode filmover mutually different facing areas. Chip capacitors of a plurality oftypes of capacitance values can thus be realized by appropriateselection and combination of the capacitor elements of differentcapacitance values. (B21) The method for manufacturing a chip capacitoraccording to B20, where the facing areas of the plurality of electrodefilm portions are set to form a geometric progression.

By the invention according to B21, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be formed on the substrate. Chip capacitors of a plurality of typesof capacitance values can thereby be provided and accurate adjustment tothe desired capacitance value can be performed by appropriate selectionand combination of a plurality of the capacitor elements. (B22) Themethod for manufacturing a chip capacitor according to any one of B19 toB21, where the one electrode film and the fuses are formed of films ofthe same conductive material.

By the invention according to B22, the electrode film portions and thefuses can be formed of films of the same conductive material and canthus be formed by patterning from the same film. The manufacturingprocess is thereby simplified. (B23) A chip capacitor including asubstrate, an insulating film formed on the substrate, a lower electrodefilm formed on the insulating film, a capacitance film formed on thelower electrode film, an upper electrode film formed on the capacitancefilm so as to face the lower electrode film, a first external electrodedisposed on the insulating film and connected to the lower electrodefilm, a second external electrode disposed on the insulating film andconnected to the upper electrode film, and a pair of diodes formedinside the substrate and connected in mutually opposite directionsbetween a region including a portion directly below the first externalelectrode and a region including a portion directly below the secondexternal electrode.

With the invention according to B23, the chip capacitor can be adjustedin capacitance value accurately without being influenced by parasiticcapacitance. (B24) The chip capacitor according to B23, where the pairof diodes include an impurity diffusion region, formed in a top surfaceregion of the substrate including the portion directly below the firstexternal electrode or a portion directly below the lower electrode, andan impurity diffusion region, formed in a top surface region of thesubstrate including the portion directly below the second externalelectrode or a portion directly below the lower electrode.

By the invention according to B24, the pair of diodes can be formedeasily by forming the impurity diffusion regions. (B25) The chipcapacitor according to B24, where the substrate is a semiconductorsubstrate and the pair of diodes are formed by pn junctions of thesubstrate and the impurity regions. By the invention according to B25,the pair of diodes can be prepared readily using the pn junctions of thesemiconductors. (2) Preferred embodiments of the invention according tothe second reference example Preferred embodiments of the secondreference example shall now be described in detail with reference to theattached drawings.

FIG. 18 is a plan view of a chip capacitor according to a firstpreferred embodiment of the second reference example, and FIG. 19 is asectional view thereof showing a section taken along section lineIXX-IXX in FIG. 18. Further, FIG. 20 is an exploded perspective viewshowing the arrangement of a portion of the chip capacitor in aseparated state. The chip capacitor 51 includes a substrate 52, a firstexternal electrode 53 disposed on the substrate 52, and a secondexternal electrode 54 disposed similarly on the substrate 52. In thepresent preferred embodiment, the substrate 52 has, in a plan view, arectangular shape with the four corners chamfered. The rectangular shapehas dimensions of, for example, approximately 0.3 mm×0.15 mm. The firstexternal electrode 53 and the second external electrode 54 arerespectively disposed at portions at respective ends in the longdirection of the substrate 52. In the present preferred embodiment, eachof the first external electrode 53 and the second external electrode 54has a substantially rectangular planar shape extending in the shortdirection of the substrate 52 and has chamfered portions at twolocations respectively corresponding to the corners of the substrate 52.On the substrate 52, a plurality of capacitor elements C1 to C9 aredisposed within a capacitor arrangement region 55 between the firstexternal electrode 53 and the second external electrode 54. Theplurality of capacitor elements C1 to C9 are electrically connectedrespectively to the first external electrode 53 via a plurality of fuseunits 57.

As shown in FIG. 19 and FIG. 20, an insulating film 58 is formed on thetop surface of the substrate 52, and a lower electrode film 311 isformed on the top surface of the insulating film 58. The lower electrodefilm 311 is formed to spread across substantially the entirety of thecapacitor arrangement region 55 and extend to a region directly belowthe second external electrode 54. More specifically, the lower electrodefilm 311 has a capacitor electrode region 311A functioning as a lowerelectrode in common to the capacitor elements C1 to C9 and a pad region311B for leading out to an external electrode. The capacitor electroderegion 311A is positioned in the capacitor arrangement region 55 and thepad region 311B is positioned directly below the second externalelectrode 54.

In the capacitor arrangement region 55, a capacitance film (dielectricfilm) 312 is formed so as to cover the lower electrode film 311(capacitor electrode region 311A). The capacitance film 312 iscontinuous across the entirety of the capacitor electrode region 311Aand, in the present preferred embodiment, further extends to a regiondirectly below the first external electrode 53 and covers the insulatingfilm 58 outside the capacitor arrangement region 55. An upper electrodefilm 313 is formed on the capacitance film 312. In FIG. 18, the upperelectrode film 313 is indicated with fine dots added for the sake ofclarity. The upper electrode film 313 includes a capacitor electroderegion 313A positioned in the capacitor arrangement region 55, a padregion 313B positioned directly below the first external electrode 53,and a fuse region 313C disposed between the pad region 313B and thecapacitor electrode region 313A.

In the capacitor electrode region 313A, the upper electrode film 313 isdivided into a plurality of electrode film portions 331 to 339. In thepresent preferred embodiment, the respective electrode film portions 331to 339 are all formed to rectangular shapes and extend in the form ofbands from the fuse region 313C toward the second external electrode 54.The plurality of electrode film portions 331 to 339 face the lowerelectrode film 311 across the capacitance film 312 over a plurality oftypes of facing areas. More specifically, a ratio of the facing areas ofthe electrode film portions 331 to 339 with respect to the lowerelectrode film 311 may be set to be 1:2:4:8:16:32:64:128:128. That is,the plurality of electrode film portions 331 to 339 include theplurality of electrode film portions differing in facing area and morespecifically include the plurality of electrode film portions 331 to 338(or 331 to 337 and 339) having facing areas that are set to form ageometric progression with a common ratio of 2. The plurality ofcapacitor elements C1 to C9, respectively arranged by the respectiveelectrode film portions 331 to 339 and the facing lower electrode film311 across the capacitance film 312, thus include the plurality ofcapacitor elements having mutually different capacitance values. If theratio of the facing areas of the electrode film portions 331 to 339 isas mentioned above, the ratio of the capacitance values of the capacitorelements C1 to C9 is equal to the ratio of the facing areas and is1:2:4:8:16:32:64:128:128. The plurality of capacitor elements C1 to C9thus include the plurality of capacitor elements C1 to C8 (or C1 to C7and C9) with capacitance values set to form the geometric progressionwith the common ratio of 2.

In the present preferred embodiment, the electrode film portions 331 to335 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4:8:16. Also, the electrode filmportions 335, 336, 337, 338, and 339 are formed to bands that are equalin length and have widths with the ratio thereof being set to 1:2:4:8:8.The electrode film portions 335 to 339 are formed to extend across arange from an end edge at the first external electrode 53 side to an endedge at the second external electrode 54 side of the capacitorarrangement region 55, and the electrode film portions 331 to 334 areformed to be shorter than this range.

The pad region 313B is formed to be substantially similar in shape tothe first external electrode 53 and has a substantially rectangularplanar shape having two chamfered portions corresponding to cornerportions of the substrate 52. The fuse region 313C is disposed along onelong side (the long side at the inner side with respect to theperipheral edge of the substrate 52) of the pad region 313B. The fuseregion 313C includes the plurality of fuse units 57 that are alignedalong the one long side of the pad region 313B. The fuse units 57 areformed of the same material as and to be integral to the pad region 313Bof the upper electrode film 313. The plurality of electrode filmportions 331 to 339 are each formed integral to one or a plurality ofthe fuse units 57, are connected to the pad region 313B via the fuseunits 57, and are electrically connected to the first external electrode53 via the pad region 313B. Each of the electrode film portions 331 to336 of comparatively small area is connected to the pad region 313B viaa single fuse unit 57, and each of the electrode film portions 337 to339 of comparatively large area is connected to the pad region 313B viaa plurality of fuse units 57. It is not necessary for all of the fuseunits 57 to be used and, in the present preferred embodiment, a portionof the fuse units 57 is unused.

The fuse units 57 include first wide portions 57A arranged to beconnected to the pad region 313B, second wide portions 57B arranged tobe connected to the electrode film portions 331 to 339, and narrowportions 57C connecting the first and second wide portions 57A and 57B.The narrow portions 57C are arranged to be capable of being cut (fused)by laser light. Unnecessary electrode film portions among the electrodefilm portions 331 to 339 can thus be electrically disconnected from thefirst and second external electrodes 53 and 54 by cutting the fuse units57.

Although omitted from illustration in FIG. 18 and FIG. 20, the topsurface of the chip capacitor 51 that includes the top surface of theupper electrode film 313 is covered by a passivation film 59 as shown inFIG. 19. The passivation film 59 is constituted, for example, of anitride film and is formed not only to cover the upper surface of thechip capacitor 51 but also to extend to side surfaces of the substrate52 and cover the side surfaces. Further, a resin film 310, made of apolyimide resin, etc., is formed on the passivation film 59. The resinfilm 310 is formed to cover the upper surface of the chip capacitor 51and extend to the side surfaces of the substrate 52 to cover thepassivation film 59 on the side surfaces.

The passivation film 59 and the resin film 310 are protective films thatprotect the top surface of the chip capacitor 51. In these films, padopenings 321 and 322 are respectively formed in regions corresponding tothe first external electrode 53 and the second external electrode 54.The pad openings 321 and 322 penetrate through the passivation film 59and the resin film 310 so as to respectively expose a region of aportion of the pad region 313B of the upper electrode film 313 and aregion of a portion of the pad region 311B of the lower electrode film311. Further, with the present preferred embodiment, the pad opening 322corresponding to the second external electrode 54 also penetratesthrough the capacitance film 312.

The first external electrode 53 and the second external electrode 54 arerespectively embedded in the pad openings 321 and 322. The firstexternal electrode 53 is thereby bonded to the pad region 313B of theupper electrode film 313 and the second external electrode 54 is bondedto the pad region 311B of the lower electrode film 311. The first andsecond external electrodes 53 and 54 are formed to project from the topsurface of the resin film 310. The chip capacitor 51 can thereby beflip-chip bonded to a mounting substrate.

With the present preferred embodiment, for example, a semiconductorsubstrate formed of a semiconductor (for example, a p type siliconsubstrate) is used as the substrate 52. Therefore, directly below thefirst external electrode 53, a parasitic capacitance across theinsulating film 58 and the capacitance film 312 is formed between thefirst external electrode 53 and the substrate 52. Also, directly belowthe second external electrode 54, a parasitic capacitance across theinsulating film 58 is formed between the second external electrode 54and the substrate 52. These parasitic capacitances are connected inseries between the first external electrode 53 and the second externalelectrode 54 via the substrate 52. The series circuit of the parasiticcapacitances is connected in parallel with respect to the capacitorelements C1 to C9 so that the parasitic capacitances are added to thechip capacitor 51 and, in particular, hinder the adjustment of the chipcapacitor 51 to a desired capacitance value (for example, of not morethan 1 pF).

Therefore in the present preferred embodiment, an n type diffusionregion 323, doped with an n type impurity, is formed in a top surfaceregion of the substrate 52 directly below the first external electrode53 and directly below the pad region 313B. Also, an n type diffusionregion 324, doped with an n type impurity, is formed in a top surfaceregion of the substrate 52 directly below the second external electrode54 and directly below the lower electrode film 311. By thus forming thediffusion regions 323 and 324 in the top surface regions of thesubstrate 52, a diode based on a pn junction is formed across thesubstrate 52, the diffusion region 323, and the first external electrode53. Similarly, a diode based on a pn junction is also formed across thesubstrate 52, the diffusion region 324, and the second externalelectrode 54. Consequently, the electrical equivalent circuit of thechip capacitor 51 is arranged as shown in FIG. 21.

In FIG. 21, C is the proper capacitance of the chip capacitor 51 and CP1and CP2 are the respective parasitic capacitances at the first externalelectrode 53 side and the second external electrode 54 side. Theparasitic capacitances CP1 and CP2 are electrically cut off by a pair ofdiodes D1 and D2 that are formed by the pn junctions and are connectedin mutually opposite directions and the serial parasitic capacitancecircuit connecting the first external electrode 53 and the secondexternal electrode 54 is thereby separated from the external electrodes53 and 54.

FIG. 22 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor 51. The plurality of capacitor elementsC1 to C9 are connected in parallel between the first external electrode53 and the second external electrode 54. Fuses F1 to F9, each arrangedfrom one or a plurality of the fuse units 57, are interposed in seriesbetween the respective capacitor elements C1 to C9 and the firstexternal electrode 53. When all of the fuses F1 to F9 are connected, thecapacitance value of the chip capacitor 51 is equal to the total of thecapacitance values of the capacitor elements C1 to C9. When one or twoor more fuses selected from among the plurality of fuses F1 to F9 is orare cut, each capacitor element corresponding to a cut fuse isdisconnected and the capacitance value of the chip capacitor 51decreases by just the capacitance value of the disconnected capacitorelement or elements.

Therefore by measuring the capacitance value across the pad regions 311Band 313B (the total capacitance value of the capacitor elements C1 toC9) and thereafter using laser light to fuse one or a plurality of fusesselected appropriately from among the fuses F1 to F9 in accordance witha desired capacitance value, adjustment (laser trimming) to the desiredcapacitance value can be performed. In particular, if the capacitancevalues of the capacitor elements C1 to C8 are set to form a geometricprogression with a common ratio of 2, fine adjustment to the targetedcapacitance value at a precision corresponding to the capacitance valueof the capacitor element C1, which is the smallest capacitance value(value of the first term in the geometric progression), is madepossible.

For example, the capacitance values of the capacitor elements C1 to C9may be set as follows. C1=0.03125 pF C2=0.0625 pF C3=0.125 pF C4=0.25 pFC5=0.5 pF C6=1 pF C7=2 pF C8=4 pF C9=4 pF. In this case, the capacitanceof the chip capacitor 51 can be finely adjusted at a minimum adjustmentprecision of 0.03125 pF. Also, the fuses to be cut among the fuses F1 toF9 can be selected appropriately to provide the chip capacitor 51 withan arbitrary capacitance value between 0.1 pF and 10 pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C9 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 53 and thesecond external electrode 54. The capacitor elements C1 to C9 include aplurality of capacitor elements that differ in capacitance value andmore specifically include a plurality of capacitor elements withcapacitance values set to form a geometric progression. The chipcapacitor 51, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Details of respective portions of the chip capacitor 51 shall now bedescribed. The substrate 52 may have, for example, a rectangular shapeof 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2 mm×0.1 mm, etc. (preferably asize of not more than 0.4 mm×0.2 mm) in a plan view. The capacitorarrangement region 55 is generally a square region with each side havinga length corresponding to the length of the short side of the substrate52. The thickness of the substrate 52 may be approximately 150 μm. Thesubstrate 52 may, for example, be a substrate that has been thinned bygrinding or polishing from a rear surface side (surface on which thecapacitor elements C1 to C9 are not formed). As the material of thesubstrate 52, a semiconductor substrate as represented by a siliconsubstrate may be used or a glass substrate may be used or a resin filmmay be used.

The insulating film 58 may be a silicon oxide film or other oxide film.The film thickness thereof may be approximately 500 Å to 2000 Å. Thelower electrode film 311 is preferably a conductive film, a metal filmin particular, and may, for example, be an aluminum film. The lowerelectrode film 311 that is constituted of an aluminum film may be formedby a sputtering method. Similarly, the upper electrode film 313 ispreferably constituted of a conductive film, a metal film in particular,and may, for example, be an aluminum film. The upper electrode film 313that is constituted of an aluminum film may be formed by the sputteringmethod. The patterning for dividing the capacitor electrode region 313Aof the upper electrode film 313 into the electrode film portions 331 to339 and shaping the fuse region 313C into the plurality of fuse units 57may be performed by photolithography and etching processes.

The capacitance film 312 may be constituted, for example, of a siliconnitride film, and the film thickness thereof may be 500 Å to 2000 Å (forexample, 1000 Å). The capacitance film 312 may be a silicon nitride filmformed by plasma CVD (chemical vapor deposition). The passivation film59 may be constituted, for example, of a silicon nitride film and may beformed, for example, by the plasma CVD method. The film thicknessthereof may be approximately 8000 Å. As mentioned above, the resin film310 may be constituted of a polyimide film or other resin film.

Each of the first and second external electrodes 53 and 54 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the lower electrode film 311 or the upperelectrode film 313, a palladium layer laminated on the nickel layer, anda gold layer laminated on the palladium layer are laminated, and may beformed, for example, by a plating method (or more specifically, anelectroless plating method). The nickel layer contributes to improvementof adhesion with the lower electrode film 311 or the upper electrodefilm 313, and the palladium layer functions as a diffusion preventinglayer that suppresses mutual diffusion of the material of the upperelectrode film or the lower electrode film and the gold of the uppermostlayer of each of the first and second external electrodes 53 and 54.

FIG. 23 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 51. For example, a p type siliconsubstrate is prepared as the substrate 52. Then of the top surfaceregions of the substrate 52, a region to be positioned directly belowthe lower electrode film 311 and a region to be positioned directlybelow the pad region 313B of the upper electrode film 313 are doped withan n type impurity to form the n type diffusion regions 323 and 324(step S0). The insulating film 58, constituted of an oxide film (forexample, a silicon oxide film), is formed on the top surface of thesubstrate 52 by a thermal oxidation method and/or CVD method (step S1).Thereafter, the lower electrode film 311, constituted of an aluminumfilm, is formed over the entire top surface of the insulating film 58,for example, by the sputtering method (step S2). The film thickness ofthe lower electrode film 311 may be approximately 8000 Å. Thereafter, aresist pattern corresponding to the final shape of the lower electrodefilm 311 is formed on the top surface of the lower electrode film byphotolithography (step S3). The lower electrode film is etched using theresist pattern as a mask to obtain the lower electrode film 311 of thepattern shown in FIG. 18, etc. (step S4). The etching of the lowerelectrode film 311 may be performed, for example, by reactive ionetching.

Thereafter, the capacitance film 312, constituted of a silicon nitridefilm, etc., is formed on the lower electrode film 311, for example, bythe plasma CVD method (step S5). In the region in which the lowerelectrode film 311 is not formed, the capacitance film 312 is formed onthe top surface of the insulating film 58. Thereafter, the upperelectrode film 313 is formed on the capacitance film 312 (step S6). Theupper electrode film 313 is constituted, for example, of an aluminumfilm and may be formed by the sputtering method. The film thicknessthereof may be approximately 8000 Å. Thereafter, a resist patterncorresponding to the final shape of the upper electrode film 313 isformed on the top surface of the upper electrode film 313 byphotolithography (step S7). The upper electrode film 313 is patterned toits final shape (see FIG. 18, etc.) by etching using the resist patternas a mask (step S8). The upper electrode film 313 is thereby shaped tothe pattern having the plurality of electrode film portions 331 to 339in the capacitor electrode region 313A, having the plurality of fuseunits 57 in the fuse region 313C, and having the pad region 313Bconnected to the fuse units 57. The etching for patterning the upperelectrode film 313 may be performed by wet etching using an etchingliquid, such as phosphoric acid, etc., or may be performed by reactiveion etching.

Thereafter, inspection probes are contacted against the pad region 313Bof the upper electrode film 313 and the pad region 311B of the lowerelectrode film 311 to measure the total capacitance value of theplurality of capacitor elements C1 to C9 (step S9). Based on themeasured total capacitance value, the capacitor elements to bedisconnected, that is, the fuses to be cut are selected in accordancewith the targeted capacitance value of the chip capacitor 51 (step S10).

Thereafter as shown in FIG. 24A, a cover film 326, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 52 (step S11). The forming of the cover film 326 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 326 covers the patterned upper electrode film 313 and coversthe capacitance film 312 in the region in which the upper electrode film313 is not formed. The cover film 326 covers the fuse units 57 in thefuse region 313C.

From this state, the laser trimming for fusing the fuse units 57 isperformed (step S12). That is, as shown in FIG. 24B, each fuse unit 57constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 327 andthe narrow portion 57C of the fuse unit 57 is fused. The correspondingcapacitor element is thereby disconnected from the pad region 313B. Whenthe laser light 327 is irradiated on the fuse unit 57, the energy of thelaser light 327 is accumulated at a vicinity of the fuse unit 57 by theaction of the cover film 326 and the fuse unit 57 is thereby fused.

Thereafter as shown in FIG. 24C, a silicon nitride film is deposited onthe cover film 326, for example, by the plasma CVD method to form thepassivation film 59 (step S13). In the final form, the cover film 326 ismade integral with the passivation film 59 to constitute a portion ofthe passivation film 59. The passivation film 59 that is formed afterthe cutting of the fuses enters into openings in the cover film 326,destroyed at the same time as the fusing of the fuses, to protect thecut surfaces of the fuse units 57. The passivation film 59 thus preventsentry of foreign matter and entry of moisture into the cut locations ofthe fuse units 57. The passivation film 59 may be formed to have a filmthickness, for example, of approximately 8000 Å as a whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 53 and 54 are to beformed, is formed on the passivation film 59 (step S14). The passivationfilm 59 is etched using the resist pattern as a mask. The pad openingexposing the lower electrode film 311 in the pad region 311B and the padopening exposing the upper electrode film 313 in the pad region 313B arethereby formed (step S15). The etching of the passivation film 59 may beperformed by reactive ion etching. In the process of etching of thepassivation film 59, the capacitance film 312, which is similarlyconstituted of a nitride film, is also opened and the pad region 311B ofthe lower electrode film 311 is thereby exposed.

Thereafter a resin film is coated on the entire surface (step S16). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S17). The pad openings 321 and 322 penetrating through the resinfilm 310 and the passivation film 59 are thereby formed. Thereafter,heat treatment (curing) for hardening the resin film is performed (stepS18) and further, the first external electrode 53 and the secondexternal electrode 54 are grown inside the pad openings 321 and 322, forexample, by the electroless plating method (step S19). The chipcapacitor 51 of the structure shown in FIG. 18, etc., is therebyobtained.

In the patterning of the upper electrode film 313 using thephotolithography process, the electrode film portions 331 to 339 ofminute areas can be formed with high precision and the fuse units 57 ofeven finer pattern can be formed. After the patterning of the upperelectrode film 313, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 51 that is accurately adjusted to the desired capacitancevalue can be obtained.

FIG. 25 is a plan view for describing the arrangement of a chipcapacitor 325 according to a second preferred embodiment of the secondreference example. In FIG. 25, portions corresponding to respectiveportions shown in FIG. 18 are indicated using the same reference symbolsas in FIG. 18. In the first preferred embodiment, the capacitorelectrode region 313A of the upper electrode film 313 is divided intothe electrode film portions 331 to 339 each having a band shape. In thiscase, regions that cannot be used as capacitor elements are formedwithin the capacitor arrangement region 55 as shown in FIG. 18 andeffective use cannot be made of the restricted region on the smallsubstrate 52.

Therefore with the preferred embodiment shown in FIG. 25, the pluralityof electrode film portions 331 to 339 are divided into L-shapedelectrode film portions 341 to 349. For example, the electrode filmportion 349 in the arrangement of FIG. 25 can thereby be made to facethe lower electrode film 311 over an area that is 1.5 times that of theelectrode film portion 339 in the arrangement of FIG. 18. Therefore, ifthe capacitor element C9 corresponding to the electrode film portion 339in the first preferred embodiment of FIG. 18 has a capacitance of 4 pF,the capacitor element C9 can be made to have a capacitance of 6 pF byuse of the electrode film portion 349 of the present preferredembodiment. The capacitance value of the chip capacitor 51 can therebybe set over a wider range by making effective use of the interior of thecapacitor arrangement region 55.

Diffusion regions are formed in a region directly below the firstexternal electrode 53 and a region directly below the lower electrodefilm 31 that are top surface regions of the substrate 52 to form a pairof diodes by pn junctions to disconnect the parasitic capacitances inthe present preferred embodiment as well. The process for manufacturingthe chip capacitor 325 according to the present preferred embodiment ispractically the same as the process shown in FIG. 23. However, in thepatterning of the upper electrode film 313 (steps S7 and S8), thecapacitor electrode region 313A is divided into the plurality ofelectrode film portions 341 to 349 of the shapes shown in FIG. 25.

FIG. 26 is an exploded perspective view for describing the arrangementof a chip capacitor 328 according to a third preferred embodiment of thesecond reference example, and the respective portions of the chipcapacitor 328 are shown in the same manner as in FIG. 20 used fordescribing the first preferred embodiment. With the first preferredembodiment, the lower electrode film 311 has the capacitor electroderegion 311A constituted of a pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 55, andthe capacitor electrode region 313A of the upper electrode film 313 isdivided into the plurality of electrode film portions 331 to 339.

In contrast, with the present preferred embodiment, whereas thecapacitor electrode region 313A of the upper electrode film 313 isformed to a continuous film pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 55, thecapacitor electrode region 311A of the lower electrode film 311 isdivided into a plurality of electrode film portions 351 to 359. Theelectrode film portions 351 to 359 may be formed in the same shapes andarea ratio as those of the electrode film portions 331 to 339 in thefirst preferred embodiment or may be formed in the same shapes and arearatio as those of the electrode film portions 341 to 349 in the secondpreferred embodiment. A plurality of capacitor elements are thusarranged by the electrode film portions 351 to 359, the capacitance film312, and the upper electrode film 313. At least a portion of theplurality of capacitor elements constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression).

The lower electrode film 311 further has a fuse region 311C between thecapacitor electrode region 311A and the pad region 311B. In the fuseregion 311C, a plurality of fuse units 329, similar to the fuse units 57of the first preferred embodiment, are aligned in a single column alongthe pad region 311B. Each of the electrode film portions 351 to 359 isconnected to the pad region 311B via one or a plurality of the fuseunits 329.

The electrode film portions 351 to 359 face the upper electrode film 313over mutually different facing areas in the present arrangement as welland any of these can be disconnected individually by cutting the fuseunit 329. The same effects as those of the first preferred embodimentare thus obtained. In particular, by forming at least a portion of theplurality of electrode film portions 351 to 359 so as to face the upperelectrode film 313 over facing areas set to form a geometric progressionwith a common ratio of 2, a chip capacitor that is precisely adjusted tothe required capacitance value can be provided in the same manner as inthe first preferred embodiment.

As in the respective preferred embodiments described above, diffusionregions are formed in a region directly below the first externalelectrode 53 and a region directly below the second external electrode54 that are top surface regions of the substrate 52 to form a pair ofdiodes by pn junctions to disconnect the parasitic capacitances in thepresent preferred embodiment as well. The process for manufacturing thechip capacitor 328 according to the present preferred embodiment ispractically the same as the process shown in FIG. 23. However, in thepatterning of the lower electrode film 311 (steps S3 and S4), thecapacitor electrode region 311A is divided into the electrode filmportions 351 to 359 and the plurality of fuse units 329 are formed inthe fuse region 311C. Also, in the patterning of the upper electrodefilm 313 (steps S7 and S8), a plurality of electrode film portions arenot formed and fuse units are also not formed. Further, in the lasertrimming (step S12), the fuse units 329 formed in the lower electrodefilm 311 are cut by laser light. The lower electrode film 311 is coveredby the capacitance film 312 and the capacitance film 312 can thus beused as a cover film for accumulating the energy of the laser light inthe process of laser trimming. The forming of the cover film (step S11)immediately before the laser trimming may thus be omitted.

Although preferred embodiments of the second reference example have beendescribed above, the second reference example may be implemented in yetother modes as well. For example, although with each of the preferredembodiments described above, the arrangement where just one of either ofthe upper electrode film and the lower electrode film is divided intothe plurality of electrode films was described, both the upper electrodefilm and the lower electrode film may be divided into a plurality ofelectrode film portions. Further, although with each of the preferredembodiments, an example where each fuse unit is made integral with theupper electrode film or the lower electrode film was described, the fuseunits may be formed from a conductor film separate from the upperelectrode film and the lower electrode film. Further, although with eachof the preferred embodiments, an example where the plurality ofcapacitor elements include a plurality of capacitor elements havingcapacitance values that form a geometric progression with a common ratior (0<r; r≠1)=2 was described, the common ratio of the geometricprogression may be a numeral other than 2. Also with each of thepreferred embodiments, the insulating film 58 is formed on the topsurface of the substrate 52, the insulating film 58 may be omitted ifthe substrate 52 is an insulating substrate. Also, a conductivesubstrate may be used as the substrate 52, the conductive substrate maybe used as a lower electrode, and the capacitance film 312 may be formedso as to be in contact with the top surface of the conductive substrate.In this case, one of the external electrodes may be led out from a rearsurface of the conductive substrate. Further in the case of using theconductive substrate, diodes besides diodes based on pn junctions may beused to cut off the parasitic capacitances that can arise between thesubstrate and the external electrodes.

Besides the above, various design changes may be applied within thescope of the matters described as features of the invention according tothe (1) second reference example. For example, arrangements with which astep of manufacture not specified in the respective features B1 to B25is changed, omitted, or added are also included within the scope of thesecond reference example. <Invention according to a third referenceexample> (1) Features of the invention according to the third referenceexample. For example, the features of the invention according to thethird reference example are the following C1 to C23. (C1) A chipcapacitor including a substrate, a first external electrode disposed onthe substrate, a second external electrode disposed on the substrate, aplurality of capacitor elements formed on the substrate and connectedbetween the first external electrode and the second external electrode,and a plurality of fuses that are formed on the substrate, are eachinterposed between the plurality of capacitor elements and the firstexternal electrode or the second external electrode, and are capable ofdisconnecting each of the plurality of capacitor elements, and where asubstrate with a specific resistance of not less than 30 Ω·cm is used asthe substrate.

With the invention according to C1, the plurality of capacitor elementsare connected between the first and second external electrodes disposedon the substrate. The plurality of fuses that are capable ofdisconnecting each of the plurality of capacitor elements are providedbetween the plurality of capacitor elements and the first or secondexternal electrodes. A plurality of types of capacitance values can thusbe accommodated easily and rapidly by selecting and cutting one or aplurality of the fuses. In other words, a common design can be appliedto chip capacitors of a plurality of types of capacitance values. Also,the chip capacitor can be adjusted in capacitance value accuratelywithout being influenced by parasitic capacitance.

More specifically, if the specific resistance of the substrate is high,the parasitic capacitances that are formed directly below the firstexternal electrode and the second external electrode will not beelectrically connected to each other by the substrate. Therefore acircuit passing through these parasitic capacitances will not be formedbetween the first external electrode and the second external electrode.The parasitic capacitances arising between the substrate and the firstexternal electrode and the second external electrode can thus bedisconnected from the proper circuit of the chip capacitor, and a chipcapacitor, with which a semiconductor can be selected without problem asthe substrate material, can thus be manufactured. (C2) The chipcapacitor according to C1, where the substrate has a specific resistanceof not less than 100 Ω·cm.

With the invention according to C2, a substrate of greater specificresistance is used to enable the parasitic capacitances to be separatedmore reliably and enable the influences due to the parasiticcapacitances to be eliminated even if the proper capacitance of thecapacitor is small. (C3) The chip capacitor according to C1 or C2, wherethe plurality of capacitor elements have mutually different capacitancevalues.

With this arrangement, chip capacitors of various capacitance values canbe realized with a common design by combining a plurality of thecapacitor elements that differ in capacitance value. (C4) The chipcapacitor according to C3, where the capacitance values of the pluralityof capacitor elements are set to form a geometric progression. By theinvention according to C4, the capacitance value of the chip capacitorcan be adjusted accurately to a desired capacitance value by appropriateselection of a plurality of the capacitor elements to be connectedbetween the first external electrode and the second external electrode.For example, by setting the common ratio of the geometric progression to2, the capacitance value of the chip capacitor can be adjusted at theprecision of the first term of the geometric progression (term of thesmallest value in the geometric progression). (C5) The chip capacitoraccording to any one of C1 to C4, where at least one of the plurality offuses is cut.

With the invention according to C5, one or a plurality of the fuses maybe cut in the chip capacitor that has been adjusted in capacitancevalue. The capacitor elements to be connected between the first externalelectrode and the second external electrode can be selected by fusecutting and the chip capacitor of the required capacitance value canthereby be realized. (C6) The chip capacitor according to any one of C1to C5, including a lower electrode film formed on the substrate, acapacitance film formed on the lower electrode film, and an upperelectrode film formed on the capacitance film so as to face the lowerelectrode film, and where one electrode film among the upper electrodefilm and the lower electrode film includes a plurality of dividedelectrode film portions and the plurality of capacitor elements areformed by the plurality of the electrode film portions facing the otherelectrode film, among the upper electrode film and the lower electrodefilm, across the capacitance film.

With the invention according to C6, a capacitor structure is arranged bythe capacitance film being sandwiched between the lower electrode filmand the upper electrode film. One electrode film among the upperelectrode film and the lower electrode film is divided into theplurality of electrode film portions so that the respective electrodefilm portions face the other electrode film and the plurality ofcapacitor elements are thereby provided on the substrate. (C7) The chipcapacitor according to C6, where the plurality of electrode filmportions face the other electrode film over mutually different facingareas.

With the invention according to C7, the plurality of capacitor elementscorresponding to the plurality of electrode film portions that mutuallydiffer in facing area have mutually different capacitance values. Chipcapacitors of a plurality of types of capacitance values can thus berealized by appropriate combination of the capacitor elements. Morespecifically, when the fuses corresponding to the capacitor elementsother than the selected plurality of the capacitor elements are cut, thefuses are disconnected from between the first and second externalelectrodes. The disconnection enables the chip capacitor to have therequired capacitance value. (C8) The chip capacitor according to C7,where the facing areas of the plurality of electrode film portions areset to form a geometric progression.

By the invention according to C8, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting. (C9) Thechip capacitor according to any one of C6 to C8, where the plurality ofelectrode film portions and the fuses are formed of films of the sameconductive material.

By the invention according to C9, the electrode film portions and thefuses can be arranged from a conductive material film in common Eachelectrode film portion can be disconnected by cutting the fusecorresponding to the electrode film portion. (C10) The chip capacitoraccording to any one of C1 to C9, further including a protective filmformed to cover the upper electrode film and expose the first externalelectrode and the second external electrode.

By the invention according to C10, the upper electrode film can becovered by the protective film while exposing the first and secondexternal electrodes, thereby enabling a chip capacitor that is capableof realizing a plurality of types of capacitance values with a commondesign and is high in reliability to be provided. (C11) The chipcapacitor according to C10, where the protective film extends to a sidesurface of the substrate and covers the side surface.

With the invention according to C11, protection is also provided fromthe side surface of the substrate, thereby enabling further improvementof the reliability of the chip capacitor. (C12) A method formanufacturing a chip capacitor including a first external electrode anda second external electrode, the method including a step of preparing asubstrate having a specific resistance of not less than 30 Ω·cm andpreferably not less than 100 Ω·cm as the substrate, a step of forming aplurality of capacitor elements on a substrate, a step of forming, onthe substrate, a plurality of fuses that disconnectably connect each ofthe plurality of capacitor elements to the first external electrode orthe second external electrode, and a step of forming the first externalelectrode and the second external electrode on the substrate.

By the invention according to C12, chip capacitors being of a commondesign and yet being of a plurality of capacitance values can bemanufactured by cutting the fuses that are selected in accordance withthe required capacitance values. Chip capacitors that are not influencedby parasitic capacitance can also be manufactured. (C13) The method formanufacturing a chip capacitor according to C12, where the plurality ofcapacitor elements are formed to have mutually different capacitancevalues.

By the invention according to C13, a plurality of types of capacitancevalues can be realized by appropriately selecting and combining aplurality of the capacitor elements. (C14) The method for manufacturinga chip capacitor according to C13, where the capacitance values of theplurality of capacitor elements are set to form a geometric progression.With the invention according to C14, a plurality of types of capacitancevalues can be realized and fine adjustment with respect to (adjustmentto) a desired capacitance value is made possible by appropriatelyselecting and combining a plurality of the capacitor elements. Forexample, by setting the common ratio of the geometric progression to 2,the capacitance value of the chip capacitor can be adjusted at theprecision of the first term of the geometric progression (term of thesmallest value in the geometric progression). (C15) The method formanufacturing a chip capacitor according to any one of C12 to C14,further including a step of cutting at least one of the plurality offuses.

By the invention according to C15, the capacitance value of the chipcapacitor can be adjusted to the desired capacitance value byappropriately selecting each fuse to be cut. That is, the chip capacitoradjusted to the desired capacitance value can be manufactured byappropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected. (C16) The method formanufacturing a chip capacitor according to C15, further including astep of measuring a total capacitance value of the plurality ofcapacitor elements and a step of selecting each fuse to be cut based onthe measured total capacitance value, and where each selected fuse iscut in the fuse cutting step.

By the invention according to C16, the total capacitance value of theplurality of capacitor elements is measured, each fuse to be cut isselected based on the measurement result, and therefore the capacitancevalue of the chip capacitor can be set to the targeted capacitance valuereliably. (C17) The method for manufacturing a chip capacitor accordingto C15 or C16, further including a step of forming, after cutting thefuse or fuses, a protective film covering the cut portion of each fuse.

By the invention according to C17, the cut portion of each fuse iscovered by the protective film and therefore entry of foreign matter andmoisture with respect to the cut portion can be avoided to enable a chipcapacitor, which can realize a plurality of types of capacitance valueswith a common design and is high in reliability, to be manufactured.(C18) The method for manufacturing a chip capacitor according to any oneof C12 to C17, where the step of forming the plurality of capacitorelements includes a step of forming a lower electrode film on thesubstrate, a step of forming a capacitance film on the lower electrodefilm, a step of forming an upper electrode film on the capacitance filmso as to face the lower electrode film, and a step of dividing (forexample, dividing by photolithography) one electrode film among theupper electrode film and the lower electrode film into a plurality ofelectrode film portions, and the plurality of capacitor elements areformed by the plurality of electrode film portions facing the otherelectrode film, among the upper electrode film and the lower electrodefilm, across the capacitance film.

By the invention according to C18, a capacitor structure having thecapacitance film sandwiched between the lower electrode film and theupper electrode film can be formed. By one electrode film among theupper electrode film and the lower electrode film being divided into theplurality of electrode film portions, the plurality of capacitorelements, having the structure where the capacitance film is sandwichedbetween the divided electrode film portions and the other electrodefilm, can be formed on the substrate. (C19) The method for manufacturinga chip capacitor according to C18, where the one electrode film isdivided so that the plurality of electrode film portions face the otherelectrode film over mutually different facing areas.

By the invention according to C19, the plurality of capacitor elementsof different capacitance values can be formed on the substrate by makingthe plurality of electrode film portions face the other electrode filmover mutually different facing areas. Chip capacitors of a plurality oftypes of capacitance values can thus be manufactured by appropriateselection and combination of the capacitor elements of differentcapacitance values. (C20) The method for manufacturing a chip capacitoraccording to C19, where the facing areas of the plurality of electrodefilm portions are set to form a geometric progression.

By the invention according to C20, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be formed on the substrate. Chip capacitors of a plurality of typesof capacitance values can thereby be provided and accurate adjustment tothe desired capacitance value can be performed by appropriate selectionand combination of a plurality of the capacitor elements. (C21) Themethod for manufacturing a chip capacitor according to any one of C18 toC20, where the one electrode film and the fuses are formed of films ofthe same conductive material.

By the invention according to C21, the electrode film portions and thefuses can be formed of films of the same conductive material and canthus be formed by patterning from the same film. The manufacturingprocess is thereby simplified. (C22) A chip capacitor including asubstrate having a specific resistance of not less than 30 Ω·cm, aninsulating film formed on the substrate, a lower electrode film formedon the insulating film, a capacitance film formed on the lower electrodefilm, an upper electrode film formed on the capacitance film so as toface the lower electrode film, a first external electrode disposed onthe insulating film and connected to the lower electrode film, and asecond external electrode disposed on the insulating film and connectedto the upper electrode film. (C23) The chip capacitor according to C22,where the substrate has a specific resistance of not less than 100 Ω·cm.

By each of the inventions according to C22 and C23, a semiconductor canbe used as the substrate and the chip capacitor can be adjusted incapacitance value accurately without being influenced by parasiticcapacitance. (2) Preferred embodiments of the invention according to thethird reference example Preferred embodiments of the third referenceexample shall now be described in detail with reference to the attacheddrawings. FIG. 27 is a plan view of a chip capacitor according to afirst preferred embodiment of the third reference example, and FIG. 28is a sectional view thereof showing a section taken along section lineXXVIII-XXVIII in FIG. 27. Further, FIG. 29 is an exploded perspectiveview showing the arrangement of a portion of the chip capacitor in aseparated state.

The chip capacitor 61 includes a substrate 62, a first externalelectrode 63 disposed on the substrate 62, and a second externalelectrode 64 disposed similarly on the substrate 62. In the presentpreferred embodiment, the substrate 62 has, in a plan view, arectangular shape with the four corners chamfered. The rectangular shapehas dimensions of, for example, approximately 0.3 mm×0.15 mm. The firstexternal electrode 63 and the second external electrode 64 arerespectively disposed at portions at respective ends in the longdirection of the substrate 62. In the present preferred embodiment, eachof the first external electrode 63 and the second external electrode 64has a substantially rectangular planar shape extending in the shortdirection of the substrate 62 and has chamfered portions at twolocations respectively corresponding to the corners of the substrate 62.On the substrate 62, a plurality of capacitor elements C1 to C9 aredisposed within a capacitor arrangement region 65 between the firstexternal electrode 63 and the second external electrode 64. Theplurality of capacitor elements C1 to C9 are electrically connectedrespectively to the first external electrode 63 via a plurality of fuseunits 67.

As shown in FIG. 28 and FIG. 29, an insulating film 68 is formed on thetop surface of the substrate 62, and a lower electrode film 411 isformed on the top surface of the insulating film 68. The lower electrodefilm 411 is formed to spread across substantially the entirety of thecapacitor arrangement region 65 and extend to a region directly belowthe second external electrode 64. More specifically, the lower electrodefilm 411 has a capacitor electrode region 411A functioning as a lowerelectrode in common to the capacitor elements C1 to C9 and a pad region411B for leading out to an external electrode. The capacitor electroderegion 411A is positioned in the capacitor arrangement region 65 and thepad region 411B is positioned directly below the second externalelectrode 64.

In the capacitor arrangement region 65, a capacitance film (dielectricfilm) 412 is formed so as to cover the lower electrode film 411(capacitor electrode region 411A). The capacitance film 412 iscontinuous across the entirety of the capacitor electrode region 411Aand, in the present preferred embodiment, further extends to a regiondirectly below the first external electrode 63 and covers the insulatingfilm 68 outside the capacitor arrangement region 65. An upper electrodefilm 413 is formed on the capacitance film 412. In FIG. 27, the upperelectrode film 413 is indicated with fine dots added for the sake ofclarity. The upper electrode film 413 includes a capacitor electroderegion 413A positioned in the capacitor arrangement region 65, a padregion 413B positioned directly below the first external electrode 63,and a fuse region 413C disposed between the pad region 413B and thecapacitor electrode region 413A.

In the capacitor electrode region 413A, the upper electrode film 413 isdivided into a plurality of electrode film portions 431 to 439. In thepresent preferred embodiment, the respective electrode film portions 431to 439 are all formed to rectangular shapes and extend in the form ofbands from the fuse region 413C toward the second external electrode 64.The plurality of electrode film portions 431 to 439 face the lowerelectrode film 411 across the capacitance film 412 over a plurality oftypes of facing areas. More specifically, a ratio of the facing areas ofthe electrode film portions 431 to 439 with respect to the lowerelectrode film 411 may be set to be 1:2:4:8:16:32:64:128:128. That is,the plurality of electrode film portions 431 to 439 include theplurality of electrode film portions differing in facing area and morespecifically include the plurality of electrode film portions 431 to 438(or 431 to 437 and 439) having facing areas that are set to form ageometric progression with a common ratio of 2. The plurality ofcapacitor elements C1 to C9, respectively arranged by the respectiveelectrode film portions 431 to 439 and the facing lower electrode film411 across the capacitance film 412, thus include the plurality ofcapacitor elements having mutually different capacitance values. If theratio of the facing areas of the electrode film portions 431 to 439 isas mentioned above, the ratio of the capacitance values of the capacitorelements C1 to C9 is equal to the ratio of the facing areas and is1:2:4:8:16:32:64:128:128. The plurality of capacitor elements C1 to C9thus include the plurality of capacitor elements C1 to C8 (or C1 to C7and C9) with capacitance values set to form the geometric progressionwith the common ratio of 2.

In the present preferred embodiment, the electrode film portions 431 to435 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4:8:16. Also, the electrode filmportions 435, 436, 437, 438, and 439 are formed to bands that are equalin length and have widths with the ratio thereof being set to 1:2:4:8:8.The electrode film portions 435 to 439 are formed to extend across arange from an end edge at the first external electrode 63 side to an endedge at the second external electrode 64 side of the capacitorarrangement region 65, and the electrode film portions 431 to 434 areformed to be shorter than this range.

The pad region 413B is formed to be substantially similar in shape tothe first external electrode 63 and has a substantially rectangularplanar shape having two chamfered portions corresponding to cornerportions of the substrate 62. The fuse region 413C is disposed along onelong side (the long side at the inner side with respect to theperipheral edge of the substrate 62) of the pad region 413B. The fuseregion 413C includes the plurality of fuse units 67 that are alignedalong the one long side of the pad region 413B. The fuse units 67 areformed of the same material as and to be integral to the pad region 413Bof the upper electrode film 413. The plurality of electrode filmportions 431 to 439 are each formed integral to one or a plurality ofthe fuse units 67, are connected to the pad region 413B via the fuseunits 67, and are electrically connected to the first external electrode63 via the pad region 413B. Each of the electrode film portions 431 to436 of comparatively small area is connected to the pad region 413B viaa single fuse unit 67, and each of the electrode film portions 437 to439 of comparatively large area is connected to the pad region 413B viaa plurality of fuse units 67. It is not necessary for all of the fuseunits 67 to be used and, in the present preferred embodiment, a portionof the fuse units 67 is unused.

The fuse units 67 include first wide portions 67A arranged to beconnected to the pad region 413B, second wide portions 67B arranged tobe connected to the electrode film portions 431 to 439, and narrowportions 67C connecting the first and second wide portions 67A and 67B.The narrow portions 67C are arranged to be capable of being cut (fused)by laser light. Unnecessary electrode film portions among the electrodefilm portions 431 to 439 can thus be electrically disconnected from thefirst and second external electrodes 63 and 64 by cutting the fuse units67.

Although omitted from illustration in FIG. 27 and FIG. 29, the topsurface of the chip capacitor 61 that includes the top surface of theupper electrode film 413 is covered by a passivation film 69 as shown inFIG. 28. The passivation film 69 is constituted, for example, of anitride film and is formed not only to cover the upper surface of thechip capacitor 61 but also to extend to side surfaces of the substrate62 and cover the side surfaces. Further, a resin film 410, made of apolyimide resin, etc., is formed on the passivation film 69. The resinfilm 410 is formed to cover the upper surface of the chip capacitor 61and extend to the side surfaces of the substrate 62 to cover thepassivation film 69 on the side surfaces.

The passivation film 69 and the resin film 410 are protective films thatprotect the top surface of the chip capacitor 61. In these films, padopenings 414 and 415 are respectively formed in regions corresponding tothe first external electrode 63 and the second external electrode 64.The pad openings 414 and 415 penetrate through the passivation film 69and the resin film 410 so as to respectively expose a region of aportion of the pad region 413B of the upper electrode film 413 and aregion of a portion of the pad region 411B of the lower electrode film411. Further, with the present preferred embodiment, the pad opening 415corresponding to the second external electrode 64 also penetratesthrough the capacitance film 412.

The first external electrode 63 and the second external electrode 64 arerespectively embedded in the pad openings 414 and 415. The firstexternal electrode 63 is thereby bonded to the pad region 413B of theupper electrode film 413 and the second external electrode 64 is bondedto the pad region 411B of the lower electrode film 411. The first andsecond external electrodes 63 and 64 are formed to project from the topsurface of the resin film 410. The chip capacitor 61 can thereby beflip-chip bonded to a mounting substrate.

Parasitic capacitances arise in the chip capacitor 61 according to thepresent preferred embodiment. To describe with reference to FIG. 28,directly below the first external electrode 63, a parasitic capacitanceCP1 across the insulating film 68 and the capacitance film 412 is formedbetween the first external electrode 63 and the substrate 62. Also,directly below the second external electrode 64, a parasitic capacitanceCP2 across the insulating film 68 is formed between the second externalelectrode 64 and the substrate 62. These parasitic capacitances CP1 andCP2 are connected in series between the first external electrode 63 andthe second external electrode 64 via the substrate 62. By the seriescircuit of the parasitic capacitances being connected in parallel withrespect to the capacitor elements C1 to C9, the capacitance value of thechip capacitor 61 as a whole is decreased and the adjustment of the chipcapacitor 61 to a desired capacitance value is hindered.

However, in the present preferred embodiment, the substrate 62 havingthe specific resistance of not less than 30 Ω·cm and preferably not lessthan 100 Ω·cm is used as the substrate 62 so that the parasiticcapacitances CP1 and CP2 can be separated and the influences of theparasitic capacitances CP1 and CP2 on the proper capacitance of thecapacitor can be eliminated. This shall be described more specificallywith reference to FIG. 30.

FIG. 30A is an electrical equivalent circuit diagram of the chipcapacitor 61. In FIG. 30A, C is the proper capacitance of the chipcapacitor 61 and CP1 and CP2 are the respective parasitic capacitancesat the first external electrode 63 side and the second externalelectrode 64 side. R is the resistance that is present serially in theproper capacitor circuit of the chip capacitor 61. On the other hand, Rsis the resistance of the substrate 62.

The equivalent circuit of FIG. 30A can be rewritten as the equivalentcircuit shown in FIG. 30B. In FIG. 30B, Cp indicates the syntheticcapacitance of the parasitic capacitances CP1 and CP2. In the equivalentcircuit of FIG. 30B, the series circuit of R and C can be expressed bythe impedance Z0 which is a value inherent to the chip capacitor 61, andthe series circuit of the synthetic capacitance Cp and the resistance Rsof the substrate 62 can be expressed by the impedance Zp.

Then as shown in FIG. 30C, the impedance characteristics at f=5 GHz ofthe equivalent circuit including the parasitic capacitance Cp and thesubstrate resistance Rs were examined with Cp=0.3 pF and R=0.5Ω, C beingvaried as C=0.2 pF, 1 pF, and 10 pF, and Rs being varied from 10Ω· to 10MΩ.

FIG. 31 is a graph showing the impedance (Z0) characteristics of just Rand C and the impedance (Z0/Zp) characteristics when Cp and Rs aresynthesized for the case where the frequency f=5 GHz. From FIG. 31, itcan be seen that at a capacitance of not less than 0.2 pF, theresistance value of the substrate 62 must be made not less than 1 KΩ toavoid influences of the parasitic capacitances.

In regard to the specific resistance of the substrate 62 necessary formaking the resistance value of the substrate 62 not less than 1 KΩ, ifit is assumed that an effective resistance region of the substrate 62 isthe dimensions shown in FIG. 32, that is, a cubical chip with one sidebeing 0.15 mm, the specific resistance ρ (Ω·cm) must be set so thatρ*10/0.15*10/0.15*0.15/10=Rs*66.7>1 KΩ.

Therefore, ρ>15 Ω·cm is the minimum specific resistance of the substrate62. With the chip capacitor 61 of the present preferred embodiment, thesubstrate 62 has a size approximately twice the dimensions describedwith FIG. 32 and therefore the specific resistance of the substrate 62used in the chip capacitor 61 suffices to be not less than 30 Ω·cm.

The chip capacitor 61 of the present preferred embodiment ismanufactured using a silicon substrate with a specific resistance of notless than 100 Ω·cm to avoid the influences of the parasitic capacitanceseven at a low capacitance of 0.2 pF. FIG. 33 is a circuit diagram of theelectrical arrangement of the interior of the chip capacitor 61. Theplurality of capacitor elements C1 to C9 are connected in parallelbetween the first external electrode 63 and the second externalelectrode 64. Fuses F1 to F9, each arranged from one or a plurality ofthe fuse units 67, are interposed in series between the respectivecapacitor elements C1 to C9 and the first external electrode 63.

When all of the fuses F1 to F9 are connected, the capacitance value ofthe chip capacitor 61 is equal to the total of the capacitance values ofthe capacitor elements C1 to C9. When one or two or more fuses selectedfrom among the plurality of fuses F1 to F9 is or are cut, each capacitorelement corresponding to a cut fuse is disconnected and the capacitancevalue of the chip capacitor 61 decreases by just the capacitance valueof the disconnected capacitor element or elements.

Therefore by measuring the capacitance value across the pad regions 411Band 413B (the total capacitance value of the capacitor elements C1 toC9) and thereafter using laser light to fuse one or a plurality of fusesselected appropriately from among the fuses F1 to F9 in accordance witha desired capacitance value, adjustment (laser trimming) to the desiredcapacitance value can be performed. In particular, if the capacitancevalues of the capacitor elements C1 to C8 are set to form a geometricprogression with a common ratio of 2, fine adjustment to the targetedcapacitance value at a precision corresponding to the capacitance valueof the capacitor element C1, which is the smallest capacitance value(value of the first term in the geometric progression), is madepossible.

For example, the capacitance values of the capacitor elements C1 to C9may be set as follows. C1=0.03125 pF C2=0.0625 pF C3=0.125 pF C4=0.25 pFC5=0.5 pF C6=1 pF C7=2 pF C8=4 pF C9=4 pF. In this case, the capacitanceof the chip capacitor 61 can be finely adjusted at a minimum adjustmentprecision of 0.03125 pF. Also, the fuses to be cut among the fuses F1 toF9 can be selected appropriately to provide the chip capacitor 61 withan arbitrary capacitance value between 0.1 pF and 10 pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C9 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 63 and thesecond external electrode 64. The capacitor elements C1 to C9 include aplurality of capacitor elements that differ in capacitance value andmore specifically include a plurality of capacitor elements withcapacitance values set to form a geometric progression. The chipcapacitor 61, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Details of respective portions of the chip capacitor 61 shall now bedescribed. The substrate 62 may have, for example, a rectangular shapeof 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2 mm×0.1 mm, etc. (preferably asize of not more than 0.4 mm×0.2 mm) in a plan view. The capacitorarrangement region 65 is generally a square region with each side havinga length corresponding to the length of the short side of the substrate62. The thickness of the substrate 62 may be approximately 150 μm. Thesubstrate 62 may, for example, be a substrate that has been thinned bygrinding or polishing from a rear surface side (surface on which thecapacitor elements C1 to C9 are not formed). As the material of thesubstrate 62, a semiconductor substrate as represented by a siliconsubstrate may be used or a glass substrate may be used or a resin filmmay be used.

The insulating film 68 may be a silicon oxide film or other oxide film.The film thickness thereof may be approximately 500 Å to 2000 Å. Thelower electrode film 411 is preferably a conductive film, a metal filmin particular, and may, for example, be an aluminum film. The lowerelectrode film 411 that is constituted of an aluminum film may be formedby a sputtering method. Similarly, the upper electrode film 413 ispreferably constituted of a conductive film, a metal film in particular,and may, for example, be an aluminum film. The upper electrode film 413that is constituted of an aluminum film may be formed by the sputteringmethod. The patterning for dividing the capacitor electrode region 413Aof the upper electrode film 413 into the electrode film portions 431 to439 and shaping the fuse region 413C into the plurality of fuse units 67may be performed by photolithography and etching processes.

The capacitance film 412 may be constituted, for example, of a siliconnitride film, and the film thickness thereof may be 500 Å to 2000 Å (forexample, 1000 Å). The capacitance film 412 may be a silicon nitride filmformed by plasma CVD (chemical vapor deposition). The passivation film69 may be constituted, for example, of a silicon nitride film and may beformed, for example, by the plasma CVD method. The film thicknessthereof may be approximately 8000 Å. As mentioned above, the resin film410 may be constituted of a polyimide film or other resin film.

Each of the first and second external electrodes 63 and 64 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the lower electrode film 411 or the upperelectrode film 413, a palladium layer laminated on the nickel layer, anda gold layer laminated on the palladium layer are laminated, and may beformed, for example, by a plating method (or more specifically, anelectroless plating method). The nickel layer contributes to improvementof adhesion with the lower electrode film 411 or the upper electrodefilm 413, and the palladium layer functions as a diffusion preventinglayer that suppresses mutual diffusion of the material of the upperelectrode film or the lower electrode film and the gold of the uppermostlayer of each of the first and second external electrodes 63 and 64.

FIG. 34 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 61. A substrate with a specificresistance of not less than 100 Ω·cm is prepared as the substrate 62.The insulating film 68, constituted of an oxide film (for example, asilicon oxide film), is formed on the top surface of the substrate 62 bya thermal oxidation method and/or CVD method (step S1). Thereafter, thelower electrode film 411, constituted of an aluminum film, is formedover the entire top surface of the insulating film 68, for example, bythe sputtering method (step S2). The film thickness of the lowerelectrode film 411 may be approximately 8000 Å. Thereafter, a resistpattern corresponding to the final shape of the lower electrode film 411is formed on the top surface of the lower electrode film byphotolithography (step S3). The lower electrode film is etched using theresist pattern as a mask to obtain the lower electrode film 411 of thepattern shown in FIG. 27, etc. (step S4). The etching of the lowerelectrode film 411 may be performed, for example, by reactive ionetching.

Thereafter, the capacitance film 412, constituted of a silicon nitridefilm, etc., is formed on the lower electrode film 411, for example, bythe plasma CVD method (step S5). In the region in which the lowerelectrode film 411 is not formed, the capacitance film 412 is formed onthe top surface of the insulating film 68. Thereafter, the upperelectrode film 413 is formed on the capacitance film 412 (step S6). Theupper electrode film 413 is constituted, for example, of an aluminumfilm and may be formed by the sputtering method. The film thicknessthereof may be approximately 8000 Å. Thereafter, a resist patterncorresponding to the final shape of the upper electrode film 413 isformed on the top surface of the upper electrode film 413 byphotolithography (step S7). The upper electrode film 413 is patterned toits final shape (see FIG. 27, etc.) by etching using the resist patternas a mask (step S8). The upper electrode film 413 is thereby shaped tothe pattern having the plurality of electrode film portions 431 to 439in the capacitor electrode region 413A, having the plurality of fuseunits 67 in the fuse region 413C, and having the pad region 413Bconnected to the fuse units 67. The etching for patterning the upperelectrode film 413 may be performed by wet etching using an etchingliquid, such as phosphoric acid, etc., or may be performed by reactiveion etching.

Thereafter, inspection probes are contacted against the pad region 413Bof the upper electrode film 413 and the pad region 411B of the lowerelectrode film 411 to measure the total capacitance value of theplurality of capacitor elements C1 to C9 (step S9). Based on themeasured total capacitance value, the capacitor elements to bedisconnected, that is, the fuses to be cut are selected in accordancewith the targeted capacitance value of the chip capacitor 61 (step S10).

Thereafter as shown in FIG. 35A, a cover film 416, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 62 (step S11). The forming of the cover film 416 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 416 covers the patterned upper electrode film 413 and coversthe capacitance film 412 in the region in which the upper electrode film413 is not formed. The cover film 416 covers the fuse units 67 in thefuse region 413C.

From this state, the laser trimming for fusing the fuse units 67 isperformed (step S12). That is, as shown in FIG. 35B, each fuse unit 67constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 417 andthe narrow portion 67C of the fuse unit 67 is fused. The correspondingcapacitor element is thereby disconnected from the pad region 413B. Whenthe laser light 417 is irradiated on the fuse unit 67, the energy of thelaser light 417 is accumulated at a vicinity of the fuse unit 67 by theaction of the cover film 416 and the fuse unit 67 is thereby fused.

Thereafter as shown in FIG. 35C, a silicon nitride film is deposited onthe cover film 416, for example, by the plasma CVD method to form thepassivation film 69 (step S13). In the final form, the cover film 416 ismade integral with the passivation film 69 to constitute a portion ofthe passivation film 69. The passivation film 69 that is formed afterthe cutting of the fuses enters into openings in the cover film 416,destroyed at the same time as the fusing of the fuses, to protect thecut surfaces of the fuse units 67. The passivation film 69 thus preventsentry of foreign matter and entry of moisture into the cut locations ofthe fuse units 67. The passivation film 69 may be formed to have a filmthickness, for example, of approximately 8000 Å as a whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 63 and 64 are to beformed, is formed on the passivation film 69 (step S14). The passivationfilm 69 is etched using the resist pattern as a mask. The pad openingexposing the lower electrode film 411 in the pad region 411B and the padopening exposing the upper electrode film 413 in the pad region 413B arethereby formed (step S15). The etching of the passivation film 69 may beperformed by reactive ion etching. In the process of etching of thepassivation film 69, the capacitance film 412, which is similarlyconstituted of a nitride film, is also opened and the pad region 411B ofthe lower electrode film 411 is thereby exposed.

Thereafter a resin film is coated on the entire surface (step S16). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S17). The pad openings 414 and 415 penetrating through the resinfilm 410 and the passivation film 69 are thereby formed. Thereafter,heat treatment (curing) for hardening the resin film is performed (stepS18) and further, the first external electrode 63 and the secondexternal electrode 64 are grown inside the pad openings 414 and 415, forexample, by the electroless plating method (step S19). The chipcapacitor 61 of the structure shown in FIG. 27, etc., is therebyobtained.

In the patterning of the upper electrode film 413 using thephotolithography process, the electrode film portions 431 to 439 ofminute areas can be formed with high precision and the fuse units 67 ofeven finer pattern can be formed. After the patterning of the upperelectrode film 413, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 61 that is accurately adjusted to the desired capacitancevalue can be obtained.

FIG. 36 is a plan view for describing the arrangement of a chipcapacitor 418 according to a second preferred embodiment of the thirdreference example. In FIG. 36, portions corresponding to respectiveportions shown in FIG. 27 are indicated using the same reference symbolsas in FIG. 27. In the first preferred embodiment, the capacitorelectrode region 413A of the upper electrode film 413 is divided intothe electrode film portions 431 to 439 each having a band shape. In thiscase, regions that cannot be used as capacitor elements are formedwithin the capacitor arrangement region 65 as shown in FIG. 27 andeffective use cannot be made of the restricted region on the smallsubstrate 62.

Therefore with the preferred embodiment shown in FIG. 36, the pluralityof electrode film portions 431 to 439 are divided into L-shapedelectrode film portions 441 to 449. For example, the electrode filmportion 449 in the arrangement of FIG. 36 can thereby be made to facethe lower electrode film 411 over an area that is 1.5 times that of theelectrode film portion 439 in the arrangement of FIG. 27. Therefore, ifthe capacitor element C9 corresponding to the electrode film portion 439in the first preferred embodiment of FIG. 27 has a capacitance of 4 pF,the capacitor element C9 can be made to have a capacitance of 6 pF byuse of the electrode film portion 449 of the present preferredembodiment. The capacitance value of the chip capacitor 418 can therebybe set over a wider range by making effective use of the interior of thecapacitor arrangement region 65.

In order to avoid receiving influences of the parasitic capacitances,the substrate 62 has a specific resistance of not less than 100 Ω·cm inthe present preferred embodiment as well. The process for manufacturingthe chip capacitor 418 according to the present preferred embodiment ispractically the same as the process shown in FIG. 34. However, in thepatterning of the upper electrode film 413 (steps S7 and S8), thecapacitor electrode region 413A is divided into the plurality ofelectrode film portions 441 to 449 of the shapes shown in FIG. 36.

FIG. 37 is an exploded perspective view for describing the arrangementof a chip capacitor 419 according to a third preferred embodiment of thethird reference example, and the respective portions of the chipcapacitor 419 are shown in the same manner as in FIG. 29 used fordescribing the first preferred embodiment. With the first preferredembodiment, the lower electrode film 411 has the capacitor electroderegion 411A constituted of a pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 65, andthe capacitor electrode region 413A of the upper electrode film 413 isdivided into the plurality of electrode film portions 431 to 439.

In contrast, with the present preferred embodiment, whereas thecapacitor electrode region 413A of the upper electrode film 413 isformed to a continuous film pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 65, thecapacitor electrode region 411A of the lower electrode film 411 isdivided into a plurality of electrode film portions 451 to 459. Theelectrode film portions 451 to 459 may be formed in the same shapes andarea ratio as those of the electrode film portions 431 to 439 in thefirst preferred embodiment or may be formed in the same shapes and arearatio as those of the electrode film portions 441 to 449 in the secondpreferred embodiment. A plurality of capacitor elements are thusarranged by the electrode film portions 451 to 459, the capacitance film412, and the upper electrode film 413. At least a portion of theplurality of capacitor elements constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression).

The lower electrode film 411 further has a fuse region 411C between thecapacitor electrode region 411A and the pad region 411B. In the fuseregion 411C, a plurality of fuse units 420, similar to the fuse units 67of the first preferred embodiment, are aligned in a single column alongthe pad region 411B. Each of the electrode film portions 451 to 459 isconnected to the pad region 411B via one or a plurality of the fuseunits 420.

The electrode film portions 451 to 459 face the upper electrode film 413over mutually different facing areas in the present arrangement as welland any of these can be disconnected individually by cutting the fuseunit 420. The same effects as those of the first preferred embodimentare thus obtained. In particular, by forming at least a portion of theplurality of electrode film portions 451 to 459 so as to face the upperelectrode film 413 over facing areas set to form a geometric progressionwith a common ratio of 2, a chip capacitor that is precisely adjusted tothe required capacitance value can be provided in the same manner as inthe first preferred embodiment.

The substrate 62 has a specific resistance of not less than 100 Ω·cm toavoid receiving influences of the parasitic capacitances in the presentpreferred embodiment as well. The process for manufacturing the chipcapacitor 419 according to the present preferred embodiment ispractically the same as the process shown in FIG. 34. However, in thepatterning of the lower electrode film 411 (steps S3 and S4), thecapacitor electrode region 411A is divided into the electrode filmportions 451 and 459 and the plurality of fuse units 420 are formed inthe fuse region 411C. Also, in the patterning of the upper electrodefilm 413 (steps S7 and S8), a plurality of electrode film portions arenot formed and fuse units are also not formed. Further, in the lasertrimming (step S12), the fuse units 420 formed in the lower electrodefilm 411 are cut by laser light. The lower electrode film 411 is coveredby the capacitance film 412 and the capacitance film 412 can thus beused as a cover film for accumulating the energy of the laser light inthe process of laser trimming. The forming of the cover film (step S11)immediately before the laser trimming may thus be omitted.

Although preferred embodiments of the third reference example have beendescribed above, the third reference example may be implemented in yetother modes as well. For example, although with each of the preferredembodiments described above, the arrangement where just one of either ofthe upper electrode film and the lower electrode film is divided intothe plurality of electrode films was described, both the upper electrodefilm and the lower electrode film may be divided into a plurality ofelectrode film portions. Further, although with each of the preferredembodiments, an example where each fuse unit is made integral with theupper electrode film or the lower electrode film was described, the fuseunits may be formed from a conductor film separate from the upperelectrode film and the lower electrode film. Further, although with eachof the preferred embodiments, an example where the plurality ofcapacitor elements include a plurality of capacitor elements havingcapacitance values that form a geometric progression with a common ratior (0<r; r≠1)=2 was described, the common ratio of the geometricprogression may be a numeral other than 2. Also with each of thepreferred embodiments, the insulating film 68 is formed on the topsurface of the substrate 62, the insulating film 68 may be omitted ifthe substrate 62 is an insulating substrate. Also, a conductivesubstrate may be used as the substrate 62, the conductive substrate maybe used as a lower electrode, and the capacitance film 412 may be formedso as to be in contact with the top surface of the conductive substrate.In this case, one of the external electrodes may be led out from a rearsurface of the conductive substrate. Further in a case of using asemiconductor substrate, the substrate 62 is formed of a semiconductorhaving a specific resistance of not less than 30 Ω·cm and preferably notless than 100 Ω·cm to avoid receiving influences of the parasiticcapacitances.

Besides the above, various design changes may be applied within thescope of the matters described as features of the invention according tothe (1) third reference example. For example, arrangements with which astep of manufacture not specified in the respective features C1 to C23is changed, omitted, or added are also included within the scope of thethird reference example. <Invention according to a fourth referenceexample> (1) Features of the invention according to the fourth referenceexample. For example, the features of the invention according to thefourth reference example are the following D1 to D22. (D1) A chipcapacitor including a substrate having a top surface with a trenchformed therein and a capacitor structure having a capacitance filmconforming to the top surface of the substrate.

With the invention according to D1, the trench is formed in the topsurface of the substrate and the capacitor structure is formed byproviding the capacitance film so as to conform to the top surface inwhich the trench is formed. The surface area of the substrate istherefore greater than an apparent surface area in a plan viewperpendicular to a principal surface of the substrate. Accordingly, thecapacitance film conforming to the top surface of the substrate has alarge area and therefore the capacitor structure can be made to have ahigh capacitance value. A chip capacitor with which both compactsubstrate size and high capacitance are realized at the same time canthus be provided. (D2) The chip capacitor according to D1, where thecapacitor structure has a plurality of capacitor elements and furtherincluding a first external electrode provided on the substrate, a secondexternal electrode provided on the substrate, and a plurality of fusesthat are formed on the substrate, are each interposed between theplurality of capacitor elements and the first external electrode or thesecond external electrode, and are capable of disconnecting each of theplurality of capacitor elements.

With the invention according to D2, the plurality of capacitor elementsare connected between the first and second external electrodes disposedon the substrate. The plurality of fuses that are capable ofdisconnecting each of the plurality of capacitor elements are providedbetween the plurality of capacitor elements and the first or secondexternal electrodes. A plurality of types of capacitance values can thusbe accommodated easily and rapidly by selecting and cutting one or aplurality of the fuses. In other words, a common design can be appliedto chip capacitors of a plurality of types of capacitance values. (D3)The chip capacitor according to D2, where the plurality of capacitorelements have mutually different capacitance values.

With the invention according to D3, chip capacitors of variouscapacitance values can be realized with a common design by combining aplurality of the capacitor elements that differ in capacitance value.(D4) The chip capacitor according to D3, where the capacitance values ofthe plurality of capacitor elements are set to form a geometricprogression. By the invention according to D4, the capacitance value ofthe chip capacitor can be adjusted accurately to a desired capacitancevalue by appropriate selection of a plurality of the capacitor elementsto be connected between the first external electrode and the secondexternal electrode. For example, by setting the common ratio of thegeometric progression to 2, the capacitance value of the chip capacitorcan be adjusted at the precision of the first term of the geometricprogression (term of the smallest value in the geometric progression).(D5) The chip capacitor according to any one of D2 to D4, where at leastone of the plurality of fuses is cut.

With the chip capacitor that has been adjusted in capacitance value, oneor a plurality of the fuses may be cut. The capacitor elements to beconnected between the first external electrode and the second externalelectrode can be selected by fuse cutting and the chip capacitor of therequired capacitance value can thereby be realized. (D6) The chipcapacitor according to any one of D2 to D5, where the capacitorstructure includes a lower electrode and an upper electrode facing eachother across the capacitance film, the lower electrode is disposed atthe substrate side with respect to the capacitance film, the upperelectrode is disposed at the side opposite to the substrate with respectto the capacitance film, and one electrode among the lower electrode andthe upper electrode includes a plurality of electrode film portionsrespectively corresponding to the plurality of capacitor elements.

With the invention according to D6, the capacitor structure is arrangedby the capacitance film being sandwiched between the lower electrode andthe upper electrode. One electrode among the upper electrode and thelower electrode is divided into the plurality of electrode film portionsso that the respective electrode film portions face the other electrodeand the plurality of capacitor elements are thereby provided on thesubstrate. (D7) The chip capacitor according to D6, where the pluralityof electrode film portions face the other electrode among the lowerelectrode and the upper electrode over mutually different facing areas.

With the invention according to D7, the plurality of capacitor elementscorresponding to the plurality of electrode film portions that mutuallydiffer in facing area have mutually different capacitance values. Chipcapacitors of a plurality of types of capacitance values can thus berealized by appropriate combination of the capacitor elements. Morespecifically, when the fuses corresponding to the capacitor elementsother than the selected plurality of the capacitor elements are cut, thefuses are disconnected from between the first and second externalelectrodes. The disconnection enables the chip capacitor to have therequired capacitance value. (D8) The chip capacitor according to D7,where the facing areas of the plurality of electrode film portions areset to form a geometric progression.

By the invention according to D8, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting. (D9) Thechip capacitor according to any one of D6 to D8, where the one electrodeis the upper electrode. (D10) The chip capacitor according to any one ofD6 to D9, where substrate is a conductive substrate, the capacitancefilm is formed to be in contact with the top surface of the substrate,and the substrate constitutes the lower electrode.

By the invention according to D10, the entire upper electrode can bemade to face the lower electrode reliably even if the upper electrode isformed so as to be shifted with respect to a designed position duringmanufacture. The precision of the capacitance values of the respectivecapacitor elements can thus be improved. The respective capacitorelements can also be simplified in structure. Further, the manufacturingprocess can also be simplified because the lower electrode can be formedat the same time as the forming of the trench. (D11) The chip capacitoraccording to D10, where one of the first external electrode and thesecond external electrode is bonded to a rear surface of the substrate.

By the invention according to D11, the region of the top surface of theconductive substrate in which one of the first external electrode andthe second external electrode is to be formed can also be usedeffectively as a space for forming the upper electrode. Consequently,maximum use can be made of the area of the top surface of the conductivesubstrate to enable an even higher capacitance to be realized. (D12) Thechip capacitor according to any one of D6 to D8, where the upperelectrode is the one electrode and the lower electrode includes aconductive film formed so as to conform to the top surface of thesubstrate. (D13) The chip capacitor according to D12, where aninsulating film is formed on the top surface of the substrate and theconductive film is formed on the top surface of the insulating film.(D14) The chip capacitor according to any one of D6 to D13, where theelectrode film portions and the fuses are formed of films of the sameconductive material.

By the invention according to D14, the electrode film portions and thefuses can be arranged from a conductive material film in common Eachelectrode film portion can be disconnected by cutting the fusecorresponding to the electrode film portion. (D15) The chip capacitoraccording to any one of D6 to D13, where the upper electrode isconstituted of an electrode film with which the top surface is formedflatly.

By the invention according to D15, the formability of a film on the topsurface of the upper electrode is improved and therefore, for example,an insulating film or a metal film (an additional electrode film, etc.)can be formed with good precision on the upper electrode. (D16) The chipcapacitor according to any one of D2 to D15, where the plurality ofcapacitor elements include at least two capacitor elements that sharesingle trench.

By the invention according to D16, the capacitance values of therespective capacitor structures can be increased by the same ratio whilemaintaining the ratio of the apparent surface areas in a plan view ofthe plurality of the capacitor elements. (D17) The chip capacitoraccording to any one of D2 to D16, where the plurality of capacitorelements include at least one capacitor element disposed in a region inwhich the trench is formed and at least one capacitor element disposedin a region in which the trench is not formed.

By the invention according to D17, a capacitor element that is desiredto be made high in capacitance can be increased in capacitance value bypositioning the capacitor element in the region in which the trench isformed. On the other hand, a capacitor element that suffices to be lowin capacitance may be positioned in the region in which trench is notformed so as not to be made high in capacitance but be capable of beingused as an element for fine adjustment of the capacitance value indesigning the capacitance value of the chip capacitor by fuse cutting.(D18) A method for manufacturing a chip capacitor including a step offorming a trench in the top surface of the substrate and a step offorming, on the top surface of the substrate in which the trench hasbeen formed, a capacitor structure having a capacitance film conformingto the top surface of the substrate.

By the invention according to D18, a chip capacitor with which bothcompact substrate size and high capacitance are realized at the sametime can thus be manufactured. (D19) The method for manufacturing a chipcapacitor according to D18 where the chip capacitor includes a firstexternal electrode and a second external electrode provided on thesubstrate, and the step of forming the capacitor structure includes astep of forming a plurality of capacitor elements, a step of forming, onthe substrate, a plurality of fuses that disconnectably connect each ofthe plurality of capacitor elements to the first external electrode orthe second external electrode, and a step of forming the first externalelectrode and the second external electrode.

By the invention according to D19, chip capacitors being of a commondesign and yet being of a plurality of capacitance values can bemanufactured by cutting the fuses that are selected in accordance withthe required capacitance values. (D20) The method for manufacturing achip capacitor according to D18 or D19, further including a step ofcutting at least one of the plurality of fuses.

By the invention according to D20, the capacitance value of the chipcapacitor can be adjusted to the desired capacitance value byappropriately selecting each fuse to be cut. That is, the chip capacitoradjusted to the desired capacitance value can be manufactured byappropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected. (D21) The method formanufacturing a chip capacitor according to D20, further including astep of measuring a total capacitance value of the plurality ofcapacitor elements and a step of selecting each fuse to be cut based onthe measured total capacitance value, and where each selected fuse iscut in the fuse cutting step.

By the invention according to D21, the total capacitance value of theplurality of capacitor elements is measured, each fuse to be cut isselected based on the measurement result, and therefore the capacitancevalue of the chip capacitor can be set to the targeted capacitance valuereliably. (D22) The method for manufacturing a chip capacitor accordingto D20 or D21, further including a step of forming, after cutting thefuse or fuses, a protective film covering the cut portion of each fuse.

By the invention according to D22, the cut portion of each fuse iscovered by the protective film and therefore entry of foreign matter andmoisture with respect to the cut portion can be avoided to enable a chipcapacitor, which can realize a plurality of types of capacitance valueswith a common design and is high in reliability, to be manufactured. (2)Preferred embodiments of the invention according to the fourth referenceexample Preferred embodiments of the fourth reference example shall nowbe described in detail with reference to the attached drawings.

FIG. 38 is a plan view of a chip capacitor according to a firstpreferred embodiment of the fourth reference example, and FIG. 39 is asectional view thereof showing a section taken along section lineXXXIX-XXXIX in FIG. 38. Further, FIG. 40 is an exploded perspective viewshowing the arrangement of a portion of the chip capacitor in aseparated state. The chip capacitor 71 includes a substrate 72, a firstexternal electrode 73 disposed on the substrate, a second externalelectrode 74 disposed similarly on the substrate 72, and a plurality ofcapacitor elements C0 to C9.

In the present preferred embodiment, the substrate 72 is a conductivesubstrate (for example, a silicon substrate with a specific resistanceof not more than 5 mΩ·cm) and has, in a plan view, a rectangular shapewith the four corners chamfered. The first external electrode 73 and thesecond external electrode 74 are respectively disposed at portions atrespective ends in the long direction of the substrate 72. In thepresent preferred embodiment, each of the first external electrode 73and the second external electrode 74 has a substantially rectangularplanar shape extending in the short direction of the substrate 72 andhas chamfered portions at two locations respectively corresponding tothe corners of the substrate 72.

Also, the substrate 72 has a capacitor electrode region 72A functioningas a lower electrode in common to the plurality of capacitor elements C0to C9 and a pad region 72B for leading out to an external electrode. Inthe present preferred embodiment, the capacitor electrode region 72Aincludes a region directly below the first external electrode 73 and aregion between the first external electrode 73 and the second externalelectrode 74. The capacitor element C0 is positioned in the region inthe capacitor electrode region 72A directly below the first externalelectrode 73 and is directly connected electrically to the firstexternal electrode 73. On the other hand, the capacitor elements C1 toC9 are positioned in the region in the capacitor electrode region 72Abetween the first external electrode 73 and the second externalelectrode 74 and are respectively connected electrically to the firstexternal electrode 73 via a plurality of fuse units 77.

The substrate 72 has a plurality of trenches 76 formed in the capacitorelectrode region 72A. In FIG. 38, the trenches 76 are indicated withdiagonal hatching for the sake of clarity. The plurality of trenches 76are formed selectively in a portion of the capacitor electrode region72A. The capacitor electrode region 72A thus further includes a trenchformation region 516 and a trench non-formation region 517. In thepresent preferred embodiment, the trench formation region 516 and thetrench non-formation region 517 are, for example, formed adjacent toeach other in the short direction of the substrate 72 so as to dividethe region between the first external electrode 73 and the secondexternal electrode 74 into two.

In the trench formation region 516, the plurality of trenches 76 areformed in the shape of mutually parallel stripes. Each trench 76 extendstoward the trench non-formation region 517 in the direction of spanningacross the trench formation region 516 and the trench non-formationregion 517 (the short direction of the substrate 72 in the presentpreferred embodiment). The pitch of the plurality of trenches 76 and thedepth, width, etc., of each trench 76 may be designed as suited inaccordance with the capacitance value required of the chip capacitor 71.

On the top surface of the substrate 72, a capacitance film (dielectricfilm) 512 is formed so as to contact the top surface of the substrate 72in the capacitor electrode region 72A. The capacitance film 512 iscontinuous across the entirety of the capacitor electrode region 72A andthe surface at one side and the other side are formed to conform to(follow) the top surface of the substrate 72. The inner surfaces of theplurality of trenches 76 are thereby covered by the capacitance film512. Also in the present preferred embodiment, the capacitance film 512is formed so as to expose the pad region 72B. A lower electrode film 511is formed on the exposed pad region 72B. The lower electrode film 511 isdirectly connected electrically to the pad region 72B of the substrate72.

An upper electrode film 513 is formed on the capacitance film 512. InFIG. 38, the upper electrode film 513 is colored for the sake ofclarity. The upper electrode film 513 has its top surface formed flatlyand includes a capacitor electrode region 513A positioned in a region ofthe capacitor electrode region 72A between the first external electrode73 and the second external electrode 74, a pad region 513B positioneddirectly below the first external electrode 73 in the capacitorelectrode region 72A, and a fuse region 513C disposed between the padregion 513B and the capacitor electrode region 513A.

In the capacitor electrode region 513A, the upper electrode film 513 isdivided into a plurality of electrode film portions 531 to 539. In thepresent preferred embodiment, among the respective electrode filmportions 531 to 539, the electrode film portions 534 to 539 are disposedin the trench formation region 516 and the electrode film portions 531to 533 are disposed in the trench non-formation region 517. Theelectrode film portions 534 to 539 disposed in the trench formationregion 516 are formed to rectangular shapes and extend in the form ofbands from the fuse region 513C toward the second external electrode 74so as to cross the plurality of trenches 76. In other words, each of theplurality of trenches 76 intersects the plurality of electrode filmportions 534 to 539 orthogonally so as to span across these portions.Each trench 76 is thereby shared by at least two of the capacitorelements C4 to C9.

The plurality of electrode film portions 534 to 539 face the capacitorelectrode region 513A of the substrate 72 across the capacitance film512 over a plurality of types of facing areas. More specifically, aratio of the apparent facing areas of the electrode film portions 534 to539 with respect to the capacitor electrode region 513A in a plan viewperpendicular to a principal surface of the substrate 72 may be set tobe 1:2:4:8:16:32. That is, the plurality of electrode film portions 534to 539 include the plurality of electrode film portions differing infacing area and more specifically include the plurality of electrodefilm portions 534 to 539 having facing areas that are set to form ageometric progression with a common ratio of 2. The plurality ofelectrode film portions 534 to 539 are also embedded at the inner sideof the capacitance film 512 in the trenches 76 and face the capacitorelectrode region 513A across the capacitance film 512 inside each trench76 as well.

The plurality of capacitor elements C4 to C9, respectively arranged bythe respective electrode film portions 534 to 539 and the substrate 72facing across the capacitance film 512, thus include the plurality ofcapacitor elements having mutually different capacitance values. If theratio of the facing areas of the electrode film portions 534 to 539 isas mentioned above, the ratio of the capacitance values of the capacitorelements C4 to C9 is equal to the ratio of the facing areas and is1:2:4:8:16:32. The plurality of capacitor elements C4 to C9 thus includethe plurality of capacitor elements C4 to C9 with capacitance values setto form the geometric progression with the common ratio of 2.

In the present preferred embodiment, the electrode film portions 534 to536 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4. Also, the electrode film portions536 to 539 are formed to bands that are equal in length and have widthswith the ratio thereof being set to 1:2:4:8. The electrode film portions536 to 539 are formed to extend across a range from an end edge at thefirst external electrode 73 side to an end edge at the second externalelectrode 74 side of the capacitor electrode region 72A, and theelectrode film portions 534 and 535 are formed to be shorter than thisrange.

On the other hand, the electrode film portions 531 to 533 disposed inthe trench non-formation region 517 are formed to L-shapes. With anarrangement where the electrode film portions are formed to have bandshapes like the electrode film portions 534 to 539, regions that cannotbe used as capacitor elements are formed as in the trench formationregion 516 shown in FIG. 38 and effective use cannot be made of therestricted region on the small substrate 72. Therefore by making theelectrode film portions have L-shapes like the electrode film portions531 to 533, the interior of the trench non-formation region 517 can beused effectively to enable the capacitance value of the chip capacitor71 to be set over a wider range. Such L-shaped electrodes may also beapplied to the electrode film portions 534 to 539 disposed in the trenchformation region 516. Oppositely, the electrode film portions 531 to 533disposed in the trench non-formation region 517 may be formed to bands.

The pad region 513B is formed to be substantially similar in shape tothe first external electrode 73 and has a substantially rectangularplanar shape having two chamfered portions corresponding to cornerportions of the substrate 72. As shown in FIG. 39, the upper surface ofthe upper electrode film 513 in the pad region 513B is in contact withthe first external electrode 73. The upper electrode film 513 in the padregion 513B functions as an electrode film portion 540. The electrodefilm portion 540 faces the capacitor electrode region 72A of thesubstrate 72 across the capacitance film 512. The electrode film portion540, the capacitance film 512, and the capacitor electrode region 72A ofthe substrate 72 constitute the capacitor element C0.

With this arrangement, not only are capacitor structures (the capacitorelements C1 to C9) formed at the top surface side of the substrate 72but a capacitor structure (the capacitor element C0) is also formed in aregion directly below the first external electrode 73. The capacitancevalue is thus increased by the use of the region directly below thefirst external electrode 73 in the chip capacitor 71. A high capacitancecan thus be realized by making maximum use of the area of the topsurface of the substrate 72 and the chip capacitor 71, with which bothcompact size and high capacitance are realized, can be provided.

The fuse region 513C includes the plurality of fuse units 77 that arealigned along the one long side of the pad region 513B. The fuse units77 are formed of the same material as and to be integral to the padregion 513B of the upper electrode film 513. The plurality of electrodefilm portions 531 to 539 are each formed integral to one or a pluralityof the fuse units 77, are connected to the pad region 513B via the fuseunits 77, and are electrically connected to the first external electrode73 via the pad region 513B. Each of the electrode film portions 531 to537 of comparatively small area is connected to the pad region 513B viaa single fuse unit 77, and each of the electrode film portions 538 and539 of comparatively large area is connected to the pad region 513B viaa plurality of fuse units 77. It is not necessary for all of the fuseunits 77 to be used and, in the present preferred embodiment, a portionof the fuse units 77 is unused.

The fuse units 77 include first wide portions 77A arranged to beconnected to the pad region 513B, second wide portions 77B arranged tobe connected to the electrode film portions 531 to 539, and narrowportions 77C connecting the first and second wide portions 77A and 77B.The narrow portions 77C are arranged to be capable of being cut (fused)by laser light. Unnecessary electrode film portions among the electrodefilm portions 531 to 539 can thus be electrically disconnected from thefirst and second external electrodes 73 and 74 by cutting the fuse units77.

Although omitted from illustration in FIG. 38 and FIG. 40, the topsurface of the chip capacitor 71 that includes the top surface of theupper electrode film 513 is covered by a passivation film 79 as shown inFIG. 39. The passivation film 79 is constituted, for example, of anitride film and is formed not only to cover the upper surface of thechip capacitor 71 but also to extend to side surfaces of the substrate72 and cover the side surfaces. Further, a resin film 510, made of apolyimide resin, etc., is formed on the passivation film 79. The resinfilm 510 is formed to cover the upper surface of the chip capacitor 71and extend to the side surfaces of the substrate 72 to cover thepassivation film 79 on the side surfaces.

The passivation film 79 and the resin film 510 are protective films thatprotect the top surface of the chip capacitor 71. In these films, padopenings 514 and 515 are respectively formed in regions corresponding tothe first external electrode 73 and the second external electrode 74.The pad openings 514 and 515 penetrate through the passivation film 79and the resin film 510 so as to respectively expose a region of aportion of the pad region 513B of the upper electrode film 513 and aregion of a portion of the lower electrode film 511.

The first external electrode 73 and the second external electrode 74 arerespectively embedded in the pad openings 514 and 515. The firstexternal electrode 73 is thereby bonded to the pad region 513B of theupper electrode film 513 and the second external electrode 74 is bondedto the lower electrode film 511. The first and second externalelectrodes 73 and 74 are formed to project from the top surface of theresin film 510. The chip capacitor 71 can thereby be flip-chip bonded toa mounting substrate.

FIG. 41 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor 71. The plurality of capacitor elementsC0 to C9 are connected in parallel between the first external electrode73 and the second external electrode 74. Fuses F1 to F9, each arrangedfrom one or a plurality of the fuse units 77, are interposed in seriesbetween the respective capacitor elements C1 to C9 and the firstexternal electrode 73. On the other hand, a fuse is not interposedbetween the capacitor element C0 and the first external electrode 73,and the capacitor element C0 is directly connected to the first externalelectrode 73.

When all of the fuses F1 to F9 are connected, the capacitance value ofthe chip capacitor 71 is equal to the total of the capacitance values ofthe capacitor elements C0 to C9. When one or two or more fuses selectedfrom among the plurality of fuses F1 to F9 is or are cut, each capacitorelement corresponding to a cut fuse is disconnected and the capacitancevalue of the chip capacitor 71 decreases by just the capacitance valueof the disconnected capacitor element or elements. When all of the fusesF1 to F9 are cut, the capacitance value of the chip capacitor 71 is thecapacitance value of the capacitor element C0.

Therefore by measuring the capacitance value across the lower electrodefilm 511 and the pad region 513B (the total capacitance value of thecapacitor elements C0 to C9) and thereafter using laser light to fuseone or a plurality of fuses selected appropriately from among the fusesF1 to F9 in accordance with a desired capacitance value, adjustment(laser trimming) to the desired capacitance value can be performed. Inparticular, if the capacitance values of the capacitor elements C1 to C9are set to form a geometric progression with a common ratio of 2, fineadjustment to the targeted capacitance value at a precisioncorresponding to the capacitance value of the capacitor element C1,which is the smallest capacitance value (value of the first term in thegeometric progression), is made possible.

For example, the capacitance values of the capacitor elements C0 to C9may be set as follows. C0=5 pF, C1=0.25 pF C2=0.5 pF C3=1 pF C4=2 pFC5=4 pF C6=8 pF C7=16 pF C8=32 pF C9=64 pF. In this case, thecapacitance of the chip capacitor 71 can be finely adjusted at a minimumadjustment precision of 0.25 pF. Also, the fuses to be cut among thefuses F1 to F9 can be selected appropriately to provide the chipcapacitor 71 with an arbitrary capacitance value between 0.1 pF and 10pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C9 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 73 and thesecond external electrode 74. Further, the capacitor element C0 directlyconnected to the first external electrode 73 is provided directly belowthe first external electrode 73. The capacitor elements C1 to C9 includea plurality of capacitor elements that differ in capacitance value andmore specifically include a plurality of capacitor elements withcapacitance values set to form a geometric progression. The chipcapacitor 71, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Moreover, the plurality of trenches 76 are formed in the substrate 72and the capacitor structures (capacitor elements C4 to C9) are formed bythe capacitance film being provided so as to conform to the top surfacein which the trenches 76 are formed. Therefore in the trench formationregion 516, the surface area of the substrate 72 is greater than theapparent surface area in the plan view perpendicular to the principalsurface of the substrate 72. Accordingly, the capacitance film 512conforming to the top surface of the substrate 72 has a large area andthe capacitor elements C4 to C9 can thus be made to have highcapacitance values. The chip capacitor with which both compact size ofthe substrate 72 and high capacitance are realized can thus be provided.

Also, the substrate 72 serves as the lower electrode in common to thecapacitor structures (capacitor elements C0 to C9) and therefore even ifthe upper electrode film 513 is formed to be shifted with respect to thedesigned position during manufacture, the entirety of the upperelectrode film 513 can be made to face the lower electrode (substrate72) reliably. The respective capacitor elements C0 to C9 can thus beimproved in the precision of capacitance value. Also, the respectivecapacitor elements C0 to C9 can be simplified in structure. Further, thelower electrode can be formed at the same time as the forming of thetrenches 76, and the manufacturing process can thus be simplified.

Also, the upper electrode film 513, although being embedded in thetrenches 76, has its top surface formed flatly, and the formability ofthe passivation film 79 and the resin film 510 on the upper electrodefilm 513 can thus be improved. Also, the trenches 76 are shared by theplurality of capacitor elements C4 to C9, and therefore the capacitancevalues of the respective capacitor structures can be increased by thesame ratio while maintaining the ratio of the apparent surface areas ina plan view of the capacitor elements C4 to C9.

Further, the trenches 76 are formed selectively in a portion of thecapacitor electrode region 72A of the substrate 72 and therefore, thecapacitor elements that are desired to be made high in capacitance (C4to C9 in the present preferred embodiment) can be increased incapacitance value by positioning these in the trench formation region516. On the other hand, the capacitor elements that suffice to be low incapacitance (C1 to C3 in the present preferred embodiment) may bepositioned in the trench non-formation region 517 so as not to be madehigh in capacitance but be capable of being used as elements for fineadjustment of the capacitance value in designing the capacitance valueof the chip capacitor 71 by fuse cutting.

Details of respective portions of the chip capacitor 71 shall now bedescribed. The substrate 72 may have, for example, a rectangular shapeof 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2 mm×0.1 mm, etc. (preferably asize of not more than 0.4 mm×0.2 mm) in a plan view. The thickness ofthe substrate 72 may be approximately 150 μm. The substrate 72 may, forexample, be a substrate that has been thinned by grinding or polishingfrom a rear surface side (surface on which the capacitor elements C0 toC9 are not formed).

The lower electrode film 511 is preferably a conductive film, a metalfilm in particular, and may, for example, be an aluminum film. The lowerelectrode film 511 that is constituted of an aluminum film may be formedby a sputtering method. Similarly, the upper electrode film 513 ispreferably constituted of a conductive film, a metal film in particular,and may, for example, be an aluminum film. The upper electrode film 513that is constituted of an aluminum film may be formed by the sputteringmethod. The patterning for dividing the capacitor electrode region 513Aof the upper electrode film 513 into the electrode film portions 531 to539 and shaping the fuse region 513C into the plurality of fuse units 77may be performed by photolithography and etching processes.

The capacitance film 512 may be constituted, for example, of a siliconnitride film, and the film thickness thereof may be 500 Å to 2000 Å (forexample, 1000 Å). The capacitance film 512 may be a silicon nitride filmformed by plasma CVD (chemical vapor deposition). The passivation film79 may be constituted, for example, of a silicon nitride film and may beformed, for example, by the plasma CVD method. The film thicknessthereof may be approximately 8000 Å. As mentioned above, the resin film510 may be constituted of a polyimide film or other resin film.

Each of the first and second external electrodes 73 and 74 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the lower electrode film 511 or the upperelectrode film 513, a palladium layer laminated on the nickel layer, anda gold layer laminated on the palladium layer are laminated, and may beformed, for example, by a plating method (or more specifically, anelectroless plating method). The nickel layer contributes to improvementof adhesion with the lower electrode film 511 or the upper electrodefilm 513, and the palladium layer functions as a diffusion preventinglayer that suppresses mutual diffusion of the material of the upperelectrode film or the lower electrode film and the gold of the uppermostlayer of each of the first and second external electrodes 73 and 74.

FIG. 42 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 71. The stripe-shaped trenches 76 areformed by etching the substrate 72 from the top surface (step S1).Thereafter, the capacitance film 512, constituted of a silicon nitridefilm, etc., is formed on the substrate 72, for example, by the plasmaCVD method (step S2). The capacitance film 512 is formed so that itssurface at one side and the other side conform to the top surface of thesubstrate 72. After forming the capacitance film 512, the capacitancefilm 512 is patterned to expose the pad region 72B of the substrate 72.

Thereafter, the material of the upper electrode film 513 and the lowerelectrode film 511, which are constituted of aluminum films, is formedover the entire top surface of the capacitance film 512, for example, bythe sputtering method (step S3). At the portion at which the pad region72B is exposed, the material of the electrode film is formed so as tocontact the pad region 72B. The film thickness of each of the upperelectrode film 513 and the lower electrode film 511 may be approximately8000 Å. Thereafter, a resist pattern corresponding to the final shapesof the upper electrode film 513 and the lower electrode film 511 isformed on the top surfaces of the upper electrode film 513 and the lowerelectrode film 511 by photolithography (step S4).

The upper electrode film 513 and the lower electrode film 511 are etchedusing the resist pattern as a mask to obtain the upper electrode film513 and the lower electrode film 511 of the patterns shown in FIG. 38,etc., at the same time (step S5). The etching of the upper electrodefilm 513 and the lower electrode film 511 may be performed, for example,by reactive ion etching. The upper electrode film 513 is thereby shapedto the pattern having the plurality of electrode film portions 531 to539 in the capacitor electrode region 72A, having the plurality of fuseunits 77 in the fuse region 513C, and having the electrode film portion540 in the pad region 513B connected to the fuse units 77. The etchingfor patterning the upper electrode film 513 may be performed by wetetching using an etching liquid, such as phosphoric acid, etc., or maybe performed by reactive ion etching. Here, the electrode film portions531 to 540 and the fuse units 77 of the upper electrode film 513 areformed of films of the same conductive material and these can thus beformed by patterning from the same film. The manufacturing process isthereby simplified.

Thereafter, inspection probes are contacted against the pad region 513Bof the upper electrode film 513 and against the lower electrode film 511to measure the total capacitance value of the plurality of capacitorelements C0 to C9 (step S6). Based on the measured total capacitancevalue, the capacitor elements to be disconnected, that is, the fuses tobe cut are selected in accordance with the targeted capacitance value ofthe chip capacitor 71 (step S7).

Thereafter as shown in FIG. 43A, a cover film 518, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 72 (step S8). The forming of the cover film 518 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 518 covers the patterned upper electrode film 513 and lowerelectrode film 511 and covers the capacitance film 512 in the region inwhich the upper electrode film 513 and the lower electrode film 511 arenot formed. The cover film 518 covers the fuse units 77 in the fuseregion 513C.

From this state, the laser trimming for fusing the fuse units 77 isperformed (step S9). That is, as shown in FIG. 43B, each fuse unit 77constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 519 andthe narrow portion 77C of the fuse unit 77 is fused. The correspondingcapacitor element is thereby disconnected from the pad region 513B. Whenthe laser light 519 is irradiated on the fuse unit 77, the energy of thelaser light 519 is accumulated at a vicinity of the fuse unit 77 by theaction of the cover film 518 and the fuse unit 77 is thereby fused. Thecapacitance value of the chip capacitor 71 can thereby be set to thetargeted capacitance value reliably.

Thereafter as shown in FIG. 43C, a silicon nitride film is deposited onthe cover film 518, for example, by the plasma CVD method to form thepassivation film 79 (step S10). In the final form, the cover film 518 ismade integral with the passivation film 79 to constitute a portion ofthe passivation film 79. The passivation film 79 that is formed afterthe cutting of the fuses enters into openings in the cover film 518,destroyed at the same time as the fusing of the fuses, to protect thecut surfaces of the fuse units 77. The passivation film 79 thus preventsentry of foreign matter and entry of moisture into the cut locations ofthe fuse units 77. The passivation film 79 may be formed to have a filmthickness, for example, of approximately 8000 Å as a whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 73 and 74 are to beformed, is formed on the passivation film 79 (step S11). The passivationfilm 79 is etched using the resist pattern as a mask. The pad openingexposing the lower electrode film 511 and the pad opening exposing theupper electrode film 513 in the pad region 513B are thereby formed (stepS12). The etching of the passivation film 79 may be performed byreactive ion etching.

Thereafter, a resin film is coated on the entire surface (step S13). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S14). The pad openings 514 and 515 penetrating through the resinfilm 510 and the passivation film 79 are thereby formed. Thereafter,heat treatment (curing) for hardening the resin film is performed (stepS15) and further, the first external electrode 73 and the secondexternal electrode 74 are grown inside the pad openings 514 and 515, forexample, by the electroless plating method (step S16). The chipcapacitor 71 of the structure shown in FIG. 38, etc., is therebyobtained.

In the patterning of the upper electrode film 513 using thephotolithography process, the electrode film portions 531 to 540 ofminute areas can be formed with high precision and the fuse units 77 ofeven finer pattern can be formed. After the patterning of the upperelectrode film 513, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 71 that is accurately adjusted to the desired capacitancevalue can be obtained.

FIG. 44 is a plan view for describing the arrangement of a chipcapacitor 520 according to a second preferred embodiment of the fourthreference example. In FIG. 44, portions corresponding to respectiveportions shown in FIG. 38 are indicated using the same reference symbolsas in FIG. 38. In the first preferred embodiment, each of the electrodefilm portions 536 to 539 of the upper electrode film 513 disposed in thetrench formation region 516 is formed to a single band set to a desiredwidth. In this case, the electrode film portions 536 to 539 differmutually in width and therefore in the process of etching and finishingthe upper electrode film 513 to its final shape (steps S4 and S5 in FIG.42), the regions of the upper electrode film 513 that are to be removedby etching are distributed irregularly. Variation of etching may thusoccur.

Therefore with the preferred embodiment shown in FIG. 44, the pluralityof electrode film portions 537 to 539 are divided into electrode filmportions 547 to 549 having the same width as each other (having the samewidth as the electrode film portions 534 to 536 in the present preferredembodiment). The ratio of the areas of the electrode film portions 537to 539 is adjusted by increasing/decreasing the number of each of theelectrode film portions 547 to 549. The regions of the upper electrodefilm 513 that are to be removed by etching are thereby distributedregularly to enable the variation of etching to be reduced.

The process for manufacturing the chip capacitor 520 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 42. However, in the patterning of the upper electrode film513 (steps S4 and S5), the capacitor electrode region 513A is dividedinto the plurality of electrode film portions 531 to 539 of the shapesshown in FIG. 44. FIG. 45 is a sectional view for describing thearrangement of a chip capacitor 521 according to a third preferredembodiment of the fourth reference example. FIG. 46 is an explodedperspective view showing the arrangement of a portion of the chipcapacitor 521 of FIG. 45 in a separated state. In FIG. 45 and FIG. 46,portions corresponding to respective portions shown in FIG. 39 and FIG.40 are indicated using the same reference symbols as in FIG. 39 and FIG.40.

Although in the first preferred embodiment, the substrate 72 also servedthe function of the lower electrode of the capacitor elements C0 to C9,the lower electrode may be arranged instead by forming a lower electrodefilm 522 as a conductive film so that the surface at one side and theother side are formed to conform to (follow) the top surface of thesubstrate 72 as shown in FIG. 45 and FIG. 46. As the material of thesubstrate 72, a semiconductor substrate as represented by a siliconsubstrate may be used or a glass substrate may be used or a resin filmmay be used.

In this case, an insulating film 78 is formed so that its surface at oneside and surface at the other side conform to the top surface of thesubstrate 72 and the lower electrode film 522 is formed on the topsurface of the insulating film 78. More specifically, the lowerelectrode film 522 includes a capacitor electrode region 522Afunctioning as a lower electrode in common to the capacitor elements C1to C9 and a pad region 522B for leading out to an external electrode.The inner surfaces of the plurality of trenches 76 are thereby coveredby the laminated film made up of the insulating film 78, the lowerelectrode film 522, and the capacitance film 512. The insulating film 78may be a silicon oxide film or other oxide film. The film thicknessthereof may be approximately 500 Å to 2000 Å.

Further with the present preferred embodiment, whereas the capacitorelectrode region 513A of the upper electrode film 513 is formed to acontinuous film pattern that is continuous substantially across itsentirety, the capacitor electrode region 522A of the lower electrodefilm 522 is divided into a plurality of electrode film portions 531 to539. The electrode film portions 531 to 539 may be formed to the sameshapes and area ratio as those of the electrode film portions 531 to 539in the first preferred embodiment. A plurality of capacitor elements arethus arranged by the electrode film portions 531 to 539, the capacitancefilm 512, and the upper electrode film 513. At least a portion of theplurality of capacitor elements constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression).

The lower electrode film 522 further has a fuse region 522C between thecapacitor electrode region 522A and the pad region 522B. In the fuseregion 522C, a plurality of fuse units 523, similar to the fuse units 77of the first preferred embodiment, are aligned in a single column alongthe pad region 522B. Each of the electrode film portions 531 to 539 isconnected to the pad region 522B via one or a plurality of the fuseunits 523.

The electrode film portions 531 to 539 face the upper electrode film 513over mutually different facing areas in the present arrangement as welland any of these can be disconnected individually by cutting the fuseunit 523. The same effects as those of the first preferred embodimentare thus obtained. In particular, by forming at least a portion of theplurality of electrode film portions 531 to 539 so as to face the upperelectrode film 513 over facing areas set to form a geometric progressionwith a common ratio of 2, a chip capacitor that is precisely adjusted tothe required capacitance value can be provided in the same manner as inthe first preferred embodiment.

The process for manufacturing the chip capacitor 521 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 42. However, a step of forming the insulating film 78, astep of forming the lower electrode film 522, a step of forming theresist pattern, and a step of etching the lower electrode film 522(steps S1-2 to S1-5) are performed before forming the capacitance film512 (step S2). Specifically, after forming the trenches 76 in thesubstrate 72 (step S1), the insulating film 78, constituted of an oxidefilm (for example, a silicon oxide film), is formed on the top surfaceof the substrate 72 by a thermal oxidation method and/or CVD method(step S1-2). Thereafter, the lower electrode film 522, constituted of analuminum film, is formed over the entire top surface of the insulatingfilm 78, for example, by the sputtering method (step S1-3). The filmthickness of the lower electrode film 522 may be approximately 8000 Å.Thereafter, the resist pattern corresponding to the final shape of thelower electrode film 522 is formed on the top surface of the lowerelectrode film by photolithography (step S1-4). The lower electrode filmis etched using the resist pattern as a mask to obtain the lowerelectrode film 522 of the pattern shown in FIG. 45 and FIG. 46, etc.(step S1-5). The etching of the lower electrode film 511 may beperformed, for example, by reactive ion etching. Thereafter, thecapacitance film 512, constituted of a silicon nitride film, etc., isformed on the lower electrode film 522, for example, by the plasma CVDmethod (step S2). Also, in the forming and patterning of the upper andlower electrode films (steps S3 to S5), the lower electrode films and aplurality of electrode film portions are not formed and fuse units arealso not formed. Further, in the laser trimming (step S9), the fuseunits 523 formed in the lower electrode film 522 are cut by laser light.The lower electrode film 522 is covered by the capacitance film 512 andthe capacitance film 512 can thus be used as a cover film foraccumulating the energy of the laser light in the process of lasertrimming. The forming of the cover film (step S8) immediately before thelaser trimming may thus be omitted.

FIG. 47 is a sectional view for describing the arrangement of a chipcapacitor 524 according to a fourth preferred embodiment of the fourthreference example. In FIG. 47, portions corresponding to respectiveportions shown in FIG. 39 are indicated using the same reference symbolsas in FIG. 39. In the first preferred embodiment, the second externalelectrode 74 is disposed at the top surface side of the substrate 72 viathe lower electrode film 511. In this case, the pad region 72B of thesubstrate 72 cannot be used as a capacitor element as shown in FIG. 38and FIG. 39 and effective use cannot be made of the restricted region onthe small substrate 72.

Therefore with the preferred embodiment shown in FIG. 47, a secondexternal electrode 525 is formed so as to be in contact with the rearsurface of the substrate 72. By this arrangement, the pad region 72B ofthe substrate 72 can also be put to effective use as a formation spacefor the upper electrode film 513. Consequently, maximum use can be madeof the area of the top surface of the substrate 72 and an even highercapacitance can be realized. Also, a semiconductor device that includesa plurality of the chip capacitors 524 (multi chip) can be realized bymounting and packaging the plurality of chip capacitors 524 on a circuitsubstrate in face-up orientations in which the first external electrodes73 face upward (orientations in which the second external electrodes 525face downward). In this case, the first external electrodes 73 areelectrically connected to circuits on the circuit board, for example, bywire bonding.

The process for manufacturing the chip capacitor 524 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 42. However, in steps S3 to S5, only the upper electrodefilm 513 is formed and in the process of measuring the total capacitancevalue of the plurality of capacitor elements C0 to C9 (step S6), theinspection probes are contacted against the pad region 513B of the upperelectrode film 513 and the rear surface of the substrate 72. The secondexternal electrode 525 is formed, for example, by the sputtering methodafter growing the first external electrode 73.

Although preferred embodiments of the fourth reference example have beendescribed above, the fourth reference example may be implemented in yetother modes as well. For example, although with each of the preferredembodiments described above, the arrangement where just one of either ofthe upper electrode film and the lower electrode film is divided intothe plurality of electrode films was described, both the upper electrodefilm and the lower electrode film may be divided into a plurality ofelectrode film portions. Further, although with each of the preferredembodiments, an example where each fuse unit is made integral with theupper electrode film or the lower electrode film was described, the fuseunits may be formed from a conductor film separate from the upperelectrode film and the lower electrode film. Further, although with eachof the preferred embodiments, an example where the plurality ofcapacitor elements include a plurality of capacitor elements havingcapacitance values that form a geometric progression with a common ratior (0<r; r≠1)=2 was described, the common ratio of the geometricprogression may be a numeral other than 2. Also, although with thepreferred embodiment shown in FIG. 45 and FIG. 46, the insulating film78 is formed on the top surface of the substrate 72, the insulating film78 may be omitted if the substrate 72 is an insulating substrate.

Besides the above, various design changes may be applied within thescope of the matters described as features of the invention according tothe (1) fourth reference example. For example, arrangements with which astep of manufacture not specified in the respective features D1 to D22is changed, omitted, or added are also included within the scope of thefourth reference example. <Invention according to a fifth referenceexample> (1) Features of the invention according to the fifth referenceexample. For example, the features of the invention according to thefifth reference example are the following E1 to E22. (E1) A chipcapacitor including a substrate, a first external electrode disposed atone surface side of the substrate, a second external electrode disposedat the one surface side of the substrate, a lower electrode film formedat the one surface side of the substrate so as to extend from a regionbetween the first external electrode and the second external electrodeto between the second external electrode and the substrate and having anupper surface in contact with the first external electrode, acapacitance film formed on the lower electrode film so as to extend froma region between the first external electrode and the second externalelectrode to between the second external electrode and the substrate,and an upper electrode film formed on the capacitance film so as toextend from a region between the first external electrode and the secondexternal electrode to between the second external electrode and thesubstrate, facing the lower electrode film, and having an upper surfacein contact with the second external electrode.

With the invention according to E1, both the first external electrodeand the second external electrode are disposed at the one surface sideof the substrate. Also, a capacitor structure that includes the lowerelectrode film, the capacitance film, and the upper electrode film isdisposed at the one surface side of the substrate. With thisarrangement, the lower electrode film, the capacitance film, and theupper electrode film enter between the second external electrode and thesubstrate and a capacitor structure is also formed in a region directlybelow the second external electrode. Increase of the capacitance valueis thus realized by using the region directly below the second externalelectrode as well. A high capacitance can thereby be realized whilemaking maximum use of the area of the one surface of the substrate and achip capacitor with which both compact size and high capacitance arerealized can be provided. (E2) The chip capacitor according to E1, whereat least one of the upper electrode film and the lower electrode film isdivided into a plurality of electrode film portions and a plurality ofcapacitor elements respectively including the plurality of electrodefilm portions are formed on the substrate.

With the invention according to E2, at least one of the upper electrodefilm and the lower electrode film is divided into the plurality ofelectrode film portions so that the respective electric film portionsface the other electrode film and the plurality of capacitor elementsare thereby provided on the substrate. (E3) The chip capacitor accordingto E2, where a plurality of fuses that are capable of disconnecting eachof the plurality of capacitor elements are formed on the substrate.

With the chip capacitor according to E3, a plurality of types ofcapacitance values can be accommodated easily and rapidly by selectingand cutting one or a plurality of the fuses. In other words, a commondesign can be applied to chip capacitors of a plurality of types ofcapacitance values. (E4) The chip capacitor according to E3, where theplurality of capacitor elements have mutually different capacitancevalues.

With the invention according to E4, chip capacitors of variouscapacitance values can be realized with a common design by combining aplurality of the capacitor elements that differ in capacitance value.(E5) The chip capacitor according to E4, where the capacitance values ofthe plurality of capacitor elements are set to form a geometricprogression. By the invention according to E5, the capacitance value ofthe chip capacitor can be adjusted accurately to a desired capacitancevalue by appropriate selection of a plurality of the capacitor elementsto be connected between the first external electrode and the secondexternal electrode. For example, by setting the common ratio of thegeometric progression to 2, the capacitance value of the chip capacitorcan be adjusted at the precision of the first term of the geometricprogression (term of the smallest value in the geometric progression).(E6) The chip capacitor according to E3, where at least one of theplurality of fuses is cut.

With the invention according to E6, one or a plurality of the fuses maybe cut in the chip capacitor that has been adjusted in capacitancevalue. The capacitor elements to be connected between the first externalelectrode and the second external electrode can be selected by fusecutting and the chip capacitor of the required capacitance value canthereby be realized. (E7) The chip capacitor according to any one of E3to E6, where the fuses and the upper electrode film or the lowerelectrode film are formed of films of the same conductive material.

By the invention according to E7, the fuses and the upper electrode filmor the lower electrode film can be arranged from a conductive materialfilm in common. Also, electrode film portions (capacitor elements) ofthe upper electrode film or the lower electrode film can be disconnectedby cutting fuses corresponding to the respective electrode filmportions. (E8) The chip capacitor according to E1, where the upperelectrode film has a plurality of separated upper electrode filmportions in a region between the first external electrode and the secondexternal electrode, the plurality of the upper electrode film portionsare electrically connected to the second external electrode respectivelyvia the plurality of fuses, and the lower electrode film is formed in aregion avoiding a region directly below the fuses.

With the invention according to E8, when, for example, a fuse is cut byirradiating laser light, even if a fragment resulting from the cuttingreaches a region directly below the fuse, the lower electrode film isnot present at that region. Problems due to the fragment, such asshort-circuiting between an upper electrode film portion and the lowerelectrode film and corrosion of the lower electrode film, can thus beavoided. Also, the lower electrode film is formed in the region avoidingthe region directly below the fuses (region irradiated by laser light),and therefore when a fuse is cut, a problem of the lower electrode filmbecoming damaged due to the lower electrode film also being cut can beavoided. (E9) The chip capacitor according to E8, where the plurality ofupper electrode film portions face the lower electrode film overmutually different facing areas.

With the invention according to E9, the plurality of capacitor elementscorresponding to the plurality of upper electrode film portions thatmutually differ in facing area have mutually different capacitancevalues. Chip capacitors of a plurality of types of capacitance valuescan thus be realized by appropriate combination of the capacitorelements. More specifically, when the fuses corresponding to thecapacitor elements other than the selected plurality of the capacitorelements are cut, the fuses are disconnected from between the first andsecond external electrodes. The disconnection enables the chip capacitorto have the required capacitance value. (E10) The chip capacitoraccording to E9, where the facing areas of the plurality of upperelectrode film portions are set to form a geometric progression.

By the invention according to E10, the plurality of capacitor elements,the capacitance values of which are set to form a geometric progression,can be provided on the substrate. Chip capacitors of a plurality oftypes of capacitance values can thereby be realized and fine adjustmentof the capacitance value can also be performed by fuse cutting. (E11) Amethod for manufacturing a chip capacitor including a first externalelectrode and a second external electrode on a substrate, the methodincluding a step of forming a lower electrode film on the substrate soas to extend from a region between the first external electrode and thesecond external electrode to between the second external electrode andthe substrate, a step of forming a capacitance film on the lowerelectrode film so as to extend from a region between the first externalelectrode and the second external electrode to between the secondexternal electrode and the substrate, a step of forming an upperelectrode film facing the lower electrode film on the capacitance filmso as to extend from a region between the first external electrode andthe second external electrode to between the second external electrodeand the substrate, a step of forming the first external electrode so asto contact an upper surface of the lower electrode film, and a step offorming the second external electrode so as to contact an upper surfaceof the upper electrode film.

By the invention according to E11, a capacitor structure is formed notonly in a region between the first external electrode and the secondexternal electrode but also in a region directly below the secondexternal electrode, thereby enabling increase of the capacitance valueof the chip capacitor and therefore enabling a chip capacitor with whichboth compact size and high capacitance are realized to be provided.(E12) The method for manufacturing a chip capacitor according to E11,where at least one of the upper electrode film and the lower electrodefilm is divided into a plurality of electrode film portions and aplurality of capacitor elements respectively including the plurality ofelectrode film portions are formed on the substrate.

With the invention according to E12, at least one of the upper electrodefilm and the lower electrode film is divided into the plurality ofelectrode film portions to enable the plurality of capacitor elements ofa structure, with the capacitance film being sandwiched between thedivided electrode film portions and the other electrode film, to beformed on the substrate. (E13) The method for manufacturing a chipcapacitor according to E12, further including a step of forming, on thesubstrate, a plurality of fuses that are capable of disconnecting eachof the plurality of capacitor elements.

By the invention according to E13, chip capacitors being of a commondesign and yet being of a plurality of capacitance values can bemanufactured by cutting the fuses that are selected in accordance withthe required capacitance values. (E14) The method for manufacturing achip capacitor according to E13, where the plurality of capacitorelements are formed to have mutually different capacitance values.

By the invention according to E14, a plurality of types of capacitancevalues can be realized by appropriately selecting and combining aplurality of the capacitor elements. (E15) The method for manufacturinga chip capacitor according to E14, where the capacitance values of theplurality of capacitor elements are set to form a geometric progression.With the invention according to E15, a plurality of types of capacitancevalues can be realized and fine adjustment with respect to (adjustmentto) a desired capacitance value is made possible by appropriatelyselecting and combining a plurality of the capacitor elements. Forexample, by setting the common ratio of the geometric progression to 2,the capacitance value of the chip capacitor can be adjusted at theprecision of the first term of the geometric progression (term of thesmallest value in the geometric progression). (E16) The method formanufacturing a chip capacitor according to any one of E13 to E15,further including a step of cutting at least one of the plurality offuses.

By the invention according to E16, the capacitance value of the chipcapacitor can be adjusted to the desired capacitance value byappropriately selecting each fuse to be cut. That is, the chip capacitoradjusted to the desired capacitance value can be manufactured byappropriately selecting the capacitor elements to be connected to thefirst and second external electrodes and cutting the fuses correspondingto the capacitor elements besides those selected. (E17) The method formanufacturing a chip capacitor according to E16, further including astep of measuring a total capacitance value of the plurality ofcapacitor elements and a step of selecting each fuse to be cut based onthe measured total capacitance value, and where each selected fuse iscut in the fuse cutting step.

By the invention according to E17, the total capacitance value of theplurality of capacitor elements is measured, each fuse to be cut isselected based on the measurement result, and therefore the capacitancevalue of the chip capacitor can be set to the targeted capacitance valuereliably. (E18) The method for manufacturing a chip capacitor accordingto E16 or E17, further including a step of forming, after cutting thefuse or fuses, a protective film covering the cut portion of each fuse.

By the invention according to E18, the cut portion of each fuse iscovered by the protective film and therefore entry of foreign matter andmoisture with respect to the cut portion can be avoided to enable a chipcapacitor, which can realize a plurality of types of capacitance valueswith a common design and is high in reliability, to be manufactured.(E19) The method for manufacturing a chip capacitor according to any oneof E13 to E18, where the fuses and the upper electrode film or the lowerelectrode film are formed of films of the same conductive material.

By the invention according to E19, the fuses and the upper electrodefilm or the lower electrode film can be formed of films of the sameconductive material and can thus be formed by patterning from the samefilm. The manufacturing process is thereby simplified. (E20) The methodfor manufacturing a chip capacitor according to E11, where the upperelectrode film is formed to have a plurality of separated upperelectrode film portions in a region between the first external electrodeand the second external electrode, a step of forming a plurality offuses that disconnectably connect each of the plurality of upperelectrode film portions to the second external electrode is furtherincluded, and the lower electrode film is formed in a region avoiding aregion directly below the fuses.

With the invention according to E20, when, for example, a fuse is cut byirradiating laser light, even if a fragment resulting from the cuttingreaches a region directly below the fuse, the lower electrode film isnot present at that region. Problems due to the fragment, such asshort-circuiting between an upper electrode film portion and the lowerelectrode film and corrosion of the lower electrode film, can thus beavoided. Also, the lower electrode film is formed in the region avoidingthe region directly below the fuses (region irradiated by laser light),and therefore when a fuse is cut, a problem of the lower electrode filmbecoming damaged due to the lower electrode film also being cut can beavoided. (E21) The method for manufacturing a chip capacitor accordingto E20, where the plurality of upper electrode film portions are formedto face the lower electrode film over mutually different facing areas.

With the invention according to E21, the plurality of upper electrodefilm portions are made to face the lower electrode film over mutuallydifferent facing areas to enable the plurality of capacitor elementsthat differ in capacitance value to be formed on the substrate. Chipcapacitors of a plurality of types of capacitance values can thus bemanufactured by appropriate selection of the capacitor elements thatdiffer in capacitance value. (E22) The method for manufacturing a chipcapacitor according to E21, where the facing areas of the plurality ofupper electrode film portions are set to form a geometric progression.

With the invention according to E22, the plurality of upper electrodefilm portions are made to face the lower electrode film over mutuallydifferent facing areas to enable the plurality of capacitor elementsthat differ in capacitance value to be formed on the substrate. Chipcapacitors of a plurality of types of capacitance values can thus berealized by appropriate selection and combination of the capacitorelements that differ in capacitance value. (2) Preferred embodiments ofthe invention according to the fifth reference example Preferredembodiments of the fifth reference example shall now be described indetail with reference to the attached drawings.

FIG. 48 is a plan view of a chip capacitor according to a firstpreferred embodiment of the fifth reference example, and FIG. 49 is asectional view thereof showing a section taken along section lineXLIX-XLIX in FIG. 48. Further, FIG. 50 is an exploded perspective viewshowing the arrangement of a portion of the chip capacitor in aseparated state. The chip capacitor 81 includes a substrate 82, a firstexternal electrode 83 disposed on the substrate 82 (at one surface 82Aside of the substrate 82), and a second external electrode 84 disposedsimilarly on the substrate 82. In the present preferred embodiment, thesubstrate 82 has, in a plan view, a rectangular shape with the fourcorners chamfered. The first external electrode 83 and the secondexternal electrode 84 are respectively disposed at portions atrespective ends in the long direction of the substrate 82. In thepresent preferred embodiment, each of the first external electrode 83and the second external electrode 84 has a substantially rectangularplanar shape extending in the short direction of the substrate 82 andhas chamfered portions at two locations respectively corresponding tothe corners of the substrate 82. On the one surface 82A of the substrate82, a plurality of capacitor elements C1 to C9 are disposed within afirst capacitor arrangement region 85A between the first externalelectrode 83 and the second external electrode 84. The plurality ofcapacitor elements C1 to C9 are electrically connected respectively tothe second external electrode 84 via a plurality of fuse units 87(fuses). Also on the substrate 82, a capacitor element C0 is disposed ina second capacitor arrangement region 85B directly below the secondexternal electrode 84 (at a position overlapping with the secondexternal electrode 84 in a plan view). The capacitor element C0 isdirectly connected electrically to the second external electrode 84.Here, the entirety of the first capacitor arrangement region 85A and thesecond capacitor arrangement region 85B shall be referred to as the“capacitor arrangement region 85.”

As shown in FIG. 49 and FIG. 50, an insulating film 88 is formed on theone surface 82A of the substrate 82, and a lower electrode film 611 isformed on the top surface of the insulating film 88. The lower electrodefilm 611 is formed to spread across substantially the entirety of thecapacitor arrangement region 85. The lower electrode film 611 is thusformed to extend from first capacitor arrangement region 85A to thesecond capacitor arrangement region 85B between the second externalelectrode 84 and the substrate 82. Further, the lower electrode film 611is formed to extend to a region directly below the first externalelectrode 83. More specifically, the lower electrode film 611 has afirst capacitor electrode region 611A functioning as a lower electrodein common to the capacitor elements C1 to C9 in the first capacitorarrangement region 85A, a second capacitor electrode region 611Bfunctioning as a lower electrode of the capacitor element C0 in thesecond capacitor arrangement region 85B, and a pad region 611C forleading out to an external electrode. The first capacitor electroderegion 611A is positioned in the first capacitor arrangement region 85A,the second capacitor electrode region 611B is positioned in the secondcapacitor arrangement region 85B (directly below the second externalelectrode 84), and the pad region 611C is positioned directly below thefirst external electrode 83. An upper surface 611J of the pad region611C is in contact with the first external electrode 83.

A plurality of openings 616 are formed at a boundary between the firstcapacitor electrode region 611A and the second capacitor electroderegion 611B in the lower electrode film 611 (see FIG. 50). The pluralityof openings 616 are disposed across intervals along the short directionof the substrate 82 (see FIG. 50). Each opening 616 penetrates throughthe lower electrode film 611 in the thickness direction. The firstcapacitor electrode region 611A and the second capacitor electroderegion 611B are not continuous in regions in which the openings 616 areformed (see FIG. 49) but are continuous in regions in which the openings616 are not formed (see FIG. 50).

In the capacitor arrangement region 85, a capacitance film (dielectricfilm) 612 is formed so as to cover the lower electrode film 611 (thefirst capacitor electrode region 611A and second capacitor electroderegion 611B). The capacitance film 612 is continuous across theentireties of the first capacitor electrode region 611A (first capacitorarrangement region 85A) and the second capacitor electrode region 611B(second capacitor arrangement region 85B). The capacitance film 612 isthus formed on the lower electrode film 611 so as to extend from thefirst capacitor arrangement region 85A to the second capacitorarrangement region 85B between the second external electrode 84 and thesubstrate 82. In the present preferred embodiment, the capacitance film612 further covers the insulating film 88 outside the capacitorarrangement region 85 and inside the respective openings 616.

An upper electrode film 613 is formed on the capacitance film 612. InFIG. 48, the upper electrode film 613 is colored for the sake ofclarity. The upper electrode film 613 includes a capacitor electroderegion 613A positioned in the first capacitor arrangement region 85Abetween the first external electrode 83 and the second externalelectrode 84, a pad region 613B positioned directly below the secondexternal electrode 84 (in the second capacitor arrangement region 85B),and a fuse region 613C disposed between the capacitor electrode region613A and the pad region 613B. The upper electrode film 613 is thusformed on the capacitance film 612 to extend from the first capacitorarrangement region 85A to the second capacitor arrangement region 85Bbetween the second external electrode 84 and the substrate 82 (see FIG.49).

In the capacitor electrode region 613A, the upper electrode film 613 isdivided (separated) into a plurality of electrode film portions (upperelectrode film portions) 731 to 739. In the present preferredembodiment, the respective electrode film portions 731 to 739 are allformed to rectangular shapes and extend in the form of bands from thefuse region 613C toward the first external electrode 83. The pluralityof electrode film portions 731 to 739 face the lower electrode film 611across the capacitance film 612 over a plurality of types of facingareas. More specifically, a ratio of the facing areas of the electrodefilm portions 731 to 739 with respect to the lower electrode film 611may be set to be 1:2:4:8:16:32:64:128:128. That is, the plurality ofelectrode film portions 731 to 739 include the plurality of electrodefilm portions differing in facing area and more specifically include theplurality of electrode film portions 731 to 738 (or 731 to 737 and 739)having facing areas that are set to form a geometric progression with acommon ratio of 2. The plurality of capacitor elements C1 to C9,respectively arranged by the respective electrode film portions 731 to739 and the facing lower electrode film 611 across the capacitance film612, thus include the plurality of capacitor elements having mutuallydifferent capacitance values. If the ratio of the facing areas of theelectrode film portions 731 to 739 is as mentioned above, the ratio ofthe capacitance values of the capacitor elements C1 to C9 is equal tothe ratio of the facing areas and is 1:2:4:8:16:32:64:128:128. Theplurality of capacitor elements C1 to C9 thus include the plurality ofcapacitor elements C1 to C8 (or C1 to C7 and C9) with capacitance valuesset to form the geometric progression with the common ratio of 2.

In the present preferred embodiment, the electrode film portions 731 to735 are formed to bands that are equal in width and have lengths withthe ratio thereof being set to 1:2:4:8:16. Also, the electrode filmportions 735, 736, 737, 738, and 739 are formed to bands that are equalin length and have widths with the ratio thereof being set to 1:2:4:8:8.The electrode film portions 735 to 739 are formed to extend across arange from an end edge at the second external electrode 84 side to anend edge at the first external electrode 83 side of the first capacitorarrangement region 85A, and the electrode film portions 731 to 734 areformed to be shorter than this range.

The pad region 613B is formed to be substantially similar in shape tothe second external electrode 84 and has a substantially rectangularplanar shape having two chamfered portions corresponding to cornerportions of the substrate 82. As shown in FIG. 49, an upper surface 613Dof the upper electrode film 613 in the pad region 613B is in contactwith the second external electrode 84. The upper electrode film 613 inthe pad region 613B functions as an electrode film portion 740. Theelectrode film portion 740 faces the lower electrode film 611 in thesecond capacitor electrode region 611B across the capacitance film 612.The electrode film portion 740, the capacitance film 612, and the lowerelectrode film 611 in the second capacitor electrode region 611Bconstitute the capacitor element C0. For example, the facing area of theelectrode film portion 740 with respect to the lower electrode film 611is approximately twice the facing area of the electrode film portion 738or the electrode film portion 739 with respect to the lower electrodefilm 611 (see FIG. 48) and the capacitance value of the capacitorelement C0 is approximately twice the capacitance value of the capacitorelement C8 or the capacitor element C9.

With the present arrangement, a capacitor structure (capacitor elementsC1 to C9) is formed not only at the one surface 82A side of thesubstrate 82 but a capacitor structure (capacitor element C0) is alsoformed in a region directly below the second external electrode 84.Increase of the capacitance value is thus realized by additional use ofthe region directly below the second external electrode 84 in the chipcapacitor 81. A high capacitance can thus be realized by making maximumuse of the area of the one surface 82A side of the substrate 82 and thechip capacitor 81 with which both compact size and high capacitance arerealized can thus be provided.

The fuse region 613C is disposed along one long side (the long side atthe inner side with respect to the peripheral edge of the substrate 82)of the pad region 613B. The fuse region 613C includes the plurality offuse units 87 that are aligned along the one long side of the pad region613B. The number of the fuse units 87 and the number of the openings 616in the lower electrode film 611 are matched (see FIG. 50). A singleopening 616 is positioned directly below a single fuse unit 87. Thelower electrode film 611 is thus formed in a region avoiding regions(the openings 616) directly below the fuse units 87.

The fuse units 87 are formed of the same material as and to be integralto the pad region 613B of the upper electrode film 613. The plurality ofelectrode film portions 731 to 739 are each formed integral to one or aplurality of the fuse units 87, are connected to the pad region 613B(electrode film portion 740) via the fuse units 87, and are electricallyconnected to the second external electrode 84 via the pad region 613B.Each of the electrode film portions 731 to 736 of comparatively smallarea is connected to the pad region 613B via a single fuse unit 87, andeach of the electrode film portions 737 to 739 of comparatively largearea is connected to the pad region 613B via a plurality of fuse units87. It is not necessary for all of the fuse units 87 to be used and, inthe present preferred embodiment, a portion of the fuse units 87 isunused.

The fuse units 87 include first wide portions 87A arranged to beconnected to the pad region 613B, second wide portions 87B arranged tobe connected to the electrode film portions 731 to 739, and narrowportions 87C connecting the first and second wide portions 87A and 87B.The narrow portions 87C are arranged to be capable of being cut (fused)by laser light. Unnecessary electrode film portions among the electrodefilm portions 731 to 739 can thus be electrically disconnected from thefirst and second external electrodes 83 and 84 by cutting the fuse units87.

Although omitted from illustration in FIG. 48 and FIG. 50, the topsurface of the chip capacitor 81 that includes the top surface of theupper electrode film 613 is covered by a passivation film 89 as shown inFIG. 49. The passivation film 89 is constituted, for example, of anitride film and is formed not only to cover the upper surface of thechip capacitor 81 but also to extend to side surfaces of the substrate82 and cover the side surfaces. Further, a resin film 610, made of apolyimide resin, etc., is formed on the passivation film 89. The resinfilm 610 is formed to cover the upper surface of the chip capacitor 81and extend to the side surfaces of the substrate 82 to cover thepassivation film 89 on the side surfaces.

The passivation film 89 and the resin film 610 are protective films thatprotect the top surface of the chip capacitor 81. In these films, padopenings 621 and 622 are respectively formed in regions corresponding tothe first external electrode 83 and the second external electrode 84.The pad openings 621 and 622 penetrate through the passivation film 89and the resin film 610 so as to respectively expose a region of aportion of the pad region 611C of the lower electrode film 611 and aregion of a portion of the pad region 613B of the upper electrode film613. Further, with the present preferred embodiment, the pad opening 621corresponding to the first external electrode 83 also penetrates throughthe capacitance film 612.

The first external electrode 83 and the second external electrode 84 arerespectively embedded in the pad openings 621 and 622. The firstexternal electrode 83 is thereby bonded to the pad region 611C of thelower electrode film 611 and the second external electrode 84 is bondedto the pad region 613B of the upper electrode film 613. The first andsecond external electrodes 83 and 84 are formed to project from the topsurface of the resin film 610. The chip capacitor 81 can thereby beflip-chip bonded to a mounting substrate.

FIG. 51 is a circuit diagram of the electrical arrangement of theinterior of the chip capacitor 81. The plurality of capacitor elementsC0 to C9 are connected in parallel between the first external electrode83 and the second external electrode 84. Fuses F1 to F9, each arrangedfrom one or a plurality of the fuse units 87, are interposed in seriesbetween the respective capacitor elements C1 to C9 and the secondexternal electrode 84. On the other hand, a fuse is not interposedbetween the capacitor element C0 and the second external electrode 84,and the capacitor element C0 is directly connected to the secondexternal electrode 84.

When all of the fuses F1 to F9 are connected, the capacitance value ofthe chip capacitor 81 is equal to the total of the capacitance values ofthe capacitor elements C0 to C9. When one or two or more fuses selectedfrom among the plurality of fuses F1 to F9 is or are cut, each capacitorelement corresponding to a cut fuse is disconnected and the capacitancevalue of the chip capacitor 81 decreases by just the capacitance valueof the disconnected capacitor element or elements. When all of the fusesF1 to F9 are cut, the capacitance value of the chip capacitor 81 is thecapacitance value of the capacitor element C0.

Therefore by measuring the capacitance value across the pad regions 611Cand 613B (the total capacitance value of the capacitor elements C0 toC9) and thereafter using laser light to fuse one or a plurality of fusesselected appropriately from among the fuses F1 to F9 in accordance witha desired capacitance value, adjustment (laser trimming) to the desiredcapacitance value can be performed. In particular, if the capacitancevalues of the capacitor elements C1 to C8 are set to form a geometricprogression with a common ratio of 2, fine adjustment to the targetedcapacitance value at a precision corresponding to the capacitance valueof the capacitor element C1, which is the smallest capacitance value(value of the first term in the geometric progression), is madepossible.

For example, the capacitance values of the capacitor elements C0 to C9may be set as follows. C0=8 pF C1=0.03125 pF C2=0.0625 pF C3=0.125 pFC4=0.25 pF C5=0.5 pF C6=1 pF C7=2 pF C8=4 pF C9=4 pF. In this case, thecapacitance of the chip capacitor 81 can be finely adjusted at a minimumadjustment precision of 0.03125 pF. Also, the fuses to be cut among thefuses F1 to F9 can be selected appropriately to provide the chipcapacitor 81 with an arbitrary capacitance value between 10 pF and 18pF.

As described above, with the present preferred embodiment, the pluralityof capacitor elements C1 to C9 that can be disconnected by the fuses F1to F9 are provided between the first external electrode 83 and thesecond external electrode 84. Further, the capacitor element C0 directlyconnected to the second external electrode 84 is provided directly belowthe second external electrode 84. The capacitor elements C1 to C9include a plurality of capacitor elements that differ in capacitancevalue and more specifically include a plurality of capacitor elementswith capacitance values set to form a geometric progression. The chipcapacitor 81, which can accommodate a plurality of types of capacitancevalues without change of design and can be accurately adjusted to thedesired capacitance value by selection and fusion by laser light of oneor a plurality of fuses among the fuses F1 to F9, can thus be provided.

Details of respective portions of the chip capacitor 81 shall now bedescribed. With reference to FIG. 48, the substrate 82 may have, forexample, a rectangular shape of 0.3 mm×0.15 mm, 0.4 mm×0.2 mm, or 0.2mm×0.1 mm, etc. (preferably a size of not more than 0.4 mm×0.2 mm) in aplan view. The capacitor arrangement region 85 is generally a squareregion with each side having a length corresponding to the length of theshort side of the substrate 82. The thickness of the substrate 82 may beapproximately 150 μm. With reference to FIG. 49, the substrate 82 may,for example, be a substrate that has been thinned by grinding orpolishing from a rear surface side (surface on which the capacitorelements C0 to C9 are not formed). As the material of the substrate 82,a semiconductor substrate as represented by a silicon substrate may beused or a glass substrate may be used or a resin film may be used.

The insulating film 88 may be a silicon oxide film or other oxide film.The film thickness thereof may be approximately 500 Å to 2000 Å. Thelower electrode film 611 is preferably a conductive film, a metal filmin particular, and may, for example, be an aluminum film. The lowerelectrode film 611 that is constituted of an aluminum film may be formedby a sputtering method. Similarly, the upper electrode film 613 ispreferably constituted of a conductive film, a metal film in particular,and may, for example, be an aluminum film. The upper electrode film 613that is constituted of an aluminum film may be formed by the sputteringmethod. The patterning for dividing the capacitor electrode region 613Aof the upper electrode film 613 into the electrode film portions 731 to739, forming the electrode film portion 740 in the pad region 613B, andshaping the fuse region 613C into the plurality of fuse units 87 may beperformed by photolithography and etching processes.

The capacitance film 612 may be constituted, for example, of a siliconnitride film, and the film thickness thereof may be 500 Å to 2000 Å (forexample, 1000 Å). The capacitance film 612 may be a silicon nitride filmformed by plasma CVD (chemical vapor deposition). The passivation film89 may be constituted, for example, of a silicon nitride film and may beformed, for example, by the plasma CVD method. The film thicknessthereof may be approximately 8000 Å. As mentioned above, the resin film610 may be constituted of a polyimide film or other resin film.

Each of the first and second external electrodes 83 and 84 may, forexample, be constituted of a laminated structure film in which a nickellayer in contact with the lower electrode film 611 or the upperelectrode film 613, a palladium layer laminated on the nickel layer, anda gold layer laminated on the palladium layer are laminated, and may beformed, for example, by a plating method (or more specifically, anelectroless plating method). The nickel layer contributes to improvementof adhesion with the lower electrode film 611 or the upper electrodefilm 613, and the palladium layer functions as a diffusion preventinglayer that suppresses mutual diffusion of the material of the upperelectrode film or the lower electrode film and the gold of the uppermostlayer of each of the first and second external electrodes 83 and 84.

FIG. 52 is a flow diagram for describing an example of a process formanufacturing the chip capacitor 81. The insulating film 88, constitutedof an oxide film (for example, a silicon oxide film), is formed on thetop surface of the substrate 82 by a thermal oxidation method and/or CVDmethod (step S1). Thereafter, the lower electrode film 611, constitutedof an aluminum film, is formed over the entire top surface of theinsulating film 88, for example, by the sputtering method (step S2). Thefilm thickness of the lower electrode film 611 may be approximately 8000Å. Thereafter, a resist pattern corresponding to the final shape of thelower electrode film 611 is formed on the top surface of the lowerelectrode film by photolithography (step S3). The lower electrode filmis etched using the resist pattern as a mask to obtain the lowerelectrode film 611 of the pattern shown in FIG. 48, etc., and having theopenings 616 (see FIG. 50) (step S4). The etching of the lower electrodefilm 611 may be performed, for example, by reactive ion etching.

Thereafter, the capacitance film 612, constituted of a silicon nitridefilm, etc., is formed on the lower electrode film 611, for example, bythe plasma CVD method (step S5). In the regions in which the lowerelectrode film 611 is not formed (the inner sides of the openings 616,etc.), the capacitance film 612 is formed on the top surface of theinsulating film 88. Thereafter, the upper electrode film 613 is formedon the capacitance film 612 (step S6). The upper electrode film 613 isconstituted, for example, of an aluminum film and may be formed by thesputtering method. The film thickness thereof may be approximately 8000Å. Thereafter, a resist pattern corresponding to the final shape of theupper electrode film 613 is formed on the top surface of the upperelectrode film 613 by photolithography (step S7). The upper electrodefilm 613 is patterned to its final shape (see FIG. 48, etc.) by etchingusing the resist pattern as a mask (step S8). The upper electrode film613 is thereby shaped to the pattern having the plurality of electrodefilm portions 731 to 739 in the capacitor electrode region 613A, havingthe plurality of fuse units 87 in the fuse region 613C, having the padregion 613B connected to the fuse units 87, and having the electrodefilm portion 740 in the pad region 613B. The etching for patterning theupper electrode film 613 may be performed by wet etching using anetching liquid, such as phosphoric acid, etc., or may be performed byreactive ion etching. Here, the electrode film portions 731 to 740 andthe fuse units 87 of the upper electrode film 613 are formed of films ofthe same conductive material and these can thus be formed by patterningfrom the same film. The manufacturing process is thereby simplified.

Thereafter, inspection probes are contacted against the pad region 613Bof the upper electrode film 613 and the pad region 611C of the lowerelectrode film 611 to measure the total capacitance value of theplurality of capacitor elements C0 to C9 (step S9). Based on themeasured total capacitance value, the capacitor elements to bedisconnected, that is, the fuses to be cut are selected in accordancewith the targeted capacitance value of the chip capacitor 81 (step S10).

Thereafter, as shown in FIG. 53A, a cover film 626, constituted, forexample, of a nitride film, is formed on the entire surface of thesubstrate 82 (step S11). The forming of the cover film 626 may beperformed by the plasma CVD method and, for example, a silicon nitridefilm with a film thickness of approximately 3000 Å may be formed. Thecover film 626 covers the patterned upper electrode film 613 and coversthe capacitance film 612 in the region in which the upper electrode film613 is not formed. The cover film 626 covers the fuse units 87 in thefuse region 613C.

From this state, the laser trimming for fusing the fuse units 87 isperformed (step S12). That is, as shown in FIG. 53B, each fuse unit 87constituting a fuse selected in accordance with the measurement resultof the total capacitance value is irradiated with laser light 627 andthe narrow portion 87C of the fuse unit 87 is fused. The correspondingcapacitor element is thereby disconnected from the pad region 613B. Whenthe laser light 627 is irradiated on the fuse unit 87, the energy of thelaser light 627 is accumulated at a vicinity of the fuse unit 87 by theaction of the cover film 626 and the fuse unit 87 is thereby fused. Thecapacitance value of the chip capacitor 81 can thereby be set to thetargeted capacitance value reliably.

Here, as mentioned above, the lower electrode film 611 is formed in theregion avoiding the regions (openings 616) directly below the fuse units87. Therefore when a fuse unit 87 is cut by the laser light 627, even ifa fragment resulting from the cutting reaches the region directly belowthe fuse unit 87, the lower electrode film 611 is not present at thatregion. Problems due to the fragment, such as short-circuiting betweenthe upper electrode film 613 and the lower electrode film 611 andcorrosion of the lower electrode film 611, can thus be avoided. Also,the lower electrode film 611 is formed in the region avoiding theregions directly below the fuse units 87 (regions irradiated by thelaser light), and therefore when a fuse unit 87 is cut, a problem of thelower electrode film 611 becoming damaged due to the lower electrodefilm 611 also being cut can be avoided.

Thereafter, as shown in FIG. 53C, a silicon nitride film is deposited onthe cover film 626, for example, by the plasma CVD method to form thepassivation film 89 (step S13). In the final form, the cover film 626 ismade integral with the passivation film 89 to constitute a portion ofthe passivation film 89. The passivation film 89 that is formed afterthe cutting of the fuses enters into openings in the cover film 626,destroyed at the same time as the fusing of the fuses, to cover andprotect the cut surfaces of the fuse units 87. The passivation film 89thus prevents entry of foreign matter and entry of moisture into the cutlocations of the fuse units 87. The chip capacitor 81 which is high inreliability can thereby be manufactured. The passivation film 89 may beformed to have a film thickness, for example, of approximately 8000 Å asa whole.

Thereafter, a resist pattern, having penetrating holes at positions atwhich the first and second external electrodes 83 and 84 are to beformed, is formed on the passivation film 89 (step S14). The passivationfilm 89 is etched using the resist pattern as a mask. The pad openingexposing the lower electrode film 611 in the pad region 611C and the padopening exposing the upper electrode film 613 in the pad region 613B arethereby formed (step S15). The etching of the passivation film 89 may beperformed by reactive ion etching. In the process of etching of thepassivation film 89, the capacitance film 612, which is similarlyconstituted of a nitride film, is also opened and the pad region 611C ofthe lower electrode film 611 is thereby exposed.

Thereafter a resin film is coated on the entire surface (step S16). Asthe resin film, for example, a coating film of a photosensitivepolyimide is used. Patterning of the resin film by photolithography maybe performed by performing an exposure step and a subsequent developingstep on regions of the resin film corresponding to the pad openings(step S17). The pad openings 621 and 622 penetrating through the resinfilm 610 and the passivation film 89 are thereby formed. Thereafter,heat treatment (curing) for hardening the resin film is performed (stepS18) and further, the first external electrode 83 and the secondexternal electrode 84 are grown inside the pad openings 621 and 622, forexample, by the electroless plating method (step S19). The chipcapacitor 81 of the structure shown in FIG. 48, etc., is therebyobtained.

In the patterning of the upper electrode film 613 using thephotolithography process, the electrode film portions 731 to 740 ofminute areas can be formed with high precision and the fuse units 87 ofeven finer pattern can be formed. After the patterning of the upperelectrode film 613, the total capacitance value is measured and then thefuses to be cut are determined. By cutting the determined fuses, thechip capacitor 81 that is accurately adjusted to the desired capacitancevalue can be obtained.

Also by use of the portion directly below the second external electrode84 as an effective capacitance area, the present chip capacitor 81 ismade unlikely to be influenced by a parasitic capacitance between thesecond external electrode 84 and the substrate 82, and the chipcapacitor 81 of higher precision can thereby be provided. FIG. 54 is aplan view for describing the arrangement of a chip capacitor 631according to a second preferred embodiment of the fifth referenceexample. In FIG. 54, portions corresponding to respective portions shownin FIG. 48 are indicated using the same reference symbols as in FIG. 48.

In the first preferred embodiment, the capacitor electrode region 613Aof the upper electrode film 613 is divided into the electrode filmportions 731 to 739 each having a band shape. In this case, regions thatcannot be used as capacitor elements are formed within the capacitorarrangement region 85 as shown in FIG. 48 and effective use cannot bemade of the restricted region on the small substrate 82. Therefore withthe preferred embodiment shown in FIG. 54, the plurality of electrodefilm portions 731 to 739 are divided into L-shaped electrode filmportions 741 to 749. For example, the electrode film portion 749 in thearrangement of FIG. 54 can thereby be made to face the lower electrodefilm 611 over an area that is 1.5 times that of the electrode filmportion 739 in the arrangement of FIG. 48. Therefore, if the capacitorelement C9 corresponding to the electrode film portion 739 in the firstpreferred embodiment of FIG. 48 has a capacitance of 4 pF, the capacitorelement C9 can be made to have a capacitance of 6 pF by use of theelectrode film portion 749 of the present preferred embodiment. Thecapacitance value of the chip capacitor 81 can thereby be set over awider range by making effective use of the interior of the capacitorarrangement region 85.

The process for manufacturing the chip capacitor 631 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 52. However, in the patterning of the upper electrode film613 (steps S7 and S8), the capacitor electrode region 613A is dividedinto the plurality of electrode film portions 741 to 749 of the shapesshown in FIG. 54. FIG. 55 is an exploded perspective view for describingthe arrangement of a chip capacitor 641 according to a third preferredembodiment of the fifth reference example, and the respective portionsof the chip capacitor 641 are shown in the same manner as in FIG. 50used for describing the first preferred embodiment.

With the first preferred embodiment, the lower electrode film 611 hasthe first capacitor electrode region 611A and the second capacitorelectrode region 611B constituted of a pattern that is continuous acrosssubstantially the entirety of the capacitor arrangement region 85, andthe capacitor electrode region 613A of the upper electrode film 613 isdivided into the plurality of electrode film portions 731 to 739 (seeFIG. 50). In contrast, with the third preferred embodiment, whereas thecapacitor electrode region 613A and the pad region 613B of the upperelectrode film 613 are formed to a continuous film pattern that iscontinuous across substantially the entirety of the capacitorarrangement region 85, the first capacitor electrode region 611A and thesecond capacitor electrode region 611B of the lower electrode film 611are divided into a plurality of electrode film portions 751 to 759. Theelectrode film portions 751 to 759 may be formed in the same shapes andarea ratio as those of the electrode film portions 731 to 739 in thefirst preferred embodiment or may be formed in the same shapes and arearatio as those of the electrode film portions 741 to 749 in the secondpreferred embodiment. At least one of the electrode film portions 751 to759 (in FIG. 55, only the electrode film portion 759) extends todirectly below the second external electrode 84 in the second capacitorelectrode region 611B. A plurality of capacitor elements are thusarranged by the electrode film portions 751 to 759, the capacitance film612, and the upper electrode film 613. At least a portion of theplurality of capacitor elements constitutes a set of capacitor elementsthat differ in capacitance value (for example, with the respectivecapacitance values being set to form a geometric progression). Theelectrode film portion 751 to 759 constitute the capacitor elements C1to C9, in that order. The electrode film portion 759 in FIG. 55 is bentto an L-shape and is formed across the entirety of the second capacitorarrangement region 85B. Therefore the capacitance value of the capacitorelement C9 can be made greater than the capacitance value of thecapacitor element C8 and, for example, can be made twice the capacitancevalue of the capacitor element C8. Therefore unlike in the firstpreferred embodiment in which the capacitance values of the capacitorelements C8 and 9 are the same (see FIG. 48), the capacitance values ofall of the capacitor elements C1 to C9 can be made to form a geometricprogression.

The lower electrode film 611 further has a fuse region 611D between thefirst capacitor electrode region 611A and the pad region 611C. In thefuse region 611D, a plurality of fuse units 647, similar to the fuseunits 87 of the first preferred embodiment, are aligned in a singlecolumn along the pad region 611C. Each of the electrode film portions751 to 759 is connected to the pad region 611C via one or a plurality ofthe fuse units 647.

The electrode film portions 751 to 759 face the upper electrode film 613over mutually different facing areas in the present arrangement as welland any of these can be disconnected individually by cutting the fuseunit 647. The same effects as those of the first preferred embodimentare thus obtained. In particular, by forming at least a portion of theplurality of electrode film portions 751 to 759 so as to face the upperelectrode film 613 over facing areas set to form a geometric progressionwith a common ratio of 2, a chip capacitor that is precisely adjusted tothe required capacitance value can be provided in the same manner as inthe first preferred embodiment.

The process for manufacturing the chip capacitor 641 according to thepresent preferred embodiment is practically the same as the processshown in FIG. 52. However, in the patterning of the lower electrode film611 (steps S3 and S4), the first capacitor electrode region 611A and thesecond capacitor electrode region 611B are divided into the electrodefilm portions 751 to 759 and the plurality of fuse units 647 are formedin the fuse region 611D. Also, in the patterning of the upper electrodefilm 613 (steps S7 and S8), a plurality of electrode film portions arenot formed and fuse units are also not formed. However, the upperelectrode film 613 is patterned so as not to overlap with the respectivefuse units 647 in a plan view. Further, in the laser trimming (stepS12), the fuse units 647 formed in the lower electrode film 611 are cutby laser light. The lower electrode film 611 is covered by thecapacitance film 612 and the capacitance film 612 can thus be used as acover film for accumulating the energy of the laser light in the processof laser trimming. The forming of the cover film (step S11) immediatelybefore the laser trimming may thus be omitted. The upper electrode film613 is not cut by the laser trimming because the upper electrode film613 does not overlap with the respective fuse units 647 in a plan viewas mentioned above.

Although preferred embodiments of the fifth reference example have beendescribed above, the fifth reference example may be implemented in yetother modes as well. For example, although with each of the preferredembodiments described above, the arrangement where just one of either ofthe upper electrode film and the lower electrode film is divided intothe plurality of electrode films was described, both the upper electrodefilm and the lower electrode film may be divided into a plurality ofelectrode film portions. Further, although with each of the preferredembodiments, an example where each fuse unit is made integral with theupper electrode film or the lower electrode film was described, the fuseunits may be formed from a conductor film separate from the upperelectrode film and the lower electrode film. Further, although with eachof the preferred embodiments, an example where the plurality ofcapacitor elements include a plurality of capacitor elements havingcapacitance values that form a geometric progression with a common ratior (0<r; r≠1)=2 was described, the common ratio of the geometricprogression may be a numeral other than 2. Also with each of thepreferred embodiments, the insulating film 88 is formed on the topsurface of the substrate 82, the insulating film 88 may be omitted ifthe substrate 82 is an insulating substrate. Also, a conductivesubstrate may be used as the substrate 82, the conductive substrate maybe used as a lower electrode, and the capacitance film 612 may be formedso as to be in contact with the top surface of the conductive substrate.In this case, one of the external electrodes may be led out from a rearsurface of the conductive substrate.

Besides the above, various design changes may be applied within thescope of the matters described as features of the invention according tothe (1) fifth reference example. For example, arrangements with which astep of manufacture not specified in the respective features E1 to E22is changed, omitted, or added are also included within the scope of thefifth reference example.

DESCRIPTION OF THE SYMBOLS

C1 to C19 Capacitor elements, C21 to C29 Capacitor elements, C31 to C34Capacitor elements, F1 to F9 Fuses, F11 to F19 Fuses, F21 to F24 Fuses,1 Chip capacitor, 2 Substrate, 2A Principal surface, 3 First externalelectrode, 4 Second external electrode, 7 Fuse unit, 9 Passivation film,10 Resin film, 11 First electrode film, 12 First capacitance film,Second electrode film, 131 to 139 Electrode film portions, 141 to 149Electrode film portions, 151 to 159 Electrode film portions, 16 Thirdelectrode film, 17 Second capacitance film, 181 to 184 Electrode filmportions, 25 Chip capacitor, 26 Chip capacitor, 27 Fuse unit, 28 Fuseunit

What is claimed is:
 1. A chip capacitor comprising: a substrate having afront surface and a rear surface, the substrate made of a silicon; afirst external electrode disposed only on the front surface of thesubstrate; a second external electrode disposed only on the frontsurface of the substrate; a plurality of capacitor elements,respectively including a first electrode film formed on the substrate, afirst capacitance film formed on the first electrode film, a secondelectrode film formed on the first capacitance film so as to face thefirst electrode film, a second capacitance film formed on the secondelectrode film, and a third electrode film formed on the secondcapacitance film so as to face the second electrode film, and beingconnected between the first external electrode and the second externalelectrode; a plurality of fuses that are formed on the substrate, areeach interposed between the plurality of capacitor elements and thefirst external electrode or the second external electrode, and arecapable of disconnecting each of the plurality of capacitor elements;and an insulating film covering the front surface and a side surface ofthe substrate, the insulating film having a first opening and a secondopening, wherein the first external electrode and the second externalelectrode project upwardly from the first opening and the secondopening, respectively, the insulating film is exposed on the sidesurface of the substrate and has an exposed portion which is not coveredwith the first external electrode and the second external electrode onthe side surface of the substrate, and the rear surface of the substrateis a polishing surface.
 2. The chip capacitor according to claim 1,wherein the plurality of capacitor elements have mutually differentcapacitance values.
 3. The chip capacitor according to claim 2, whereinthe capacitance values of the plurality of capacitor elements are set toform a geometric progression.
 4. The chip capacitor according to claim1, wherein at least one of the plurality of fuses is cut.
 5. The chipcapacitor according to claim 1, wherein the second electrode film isdivided into a plurality of second electrode film portions and theplurality of fuses are connected respectively to the plurality of thesecond electrode film portions.
 6. The chip capacitor according to claim5, wherein the plurality of second electrode film portions face thefirst electrode film and the third electrode film over mutuallydifferent facing areas.
 7. The chip capacitor according to claim 6,wherein the facing areas of the plurality of second electrode filmportions are set to form a geometric progression.
 8. The chip capacitoraccording to claim 5, wherein the fuses and the first electrode film,the second electrode film, or the third electrode film are formed offilms of the same conductive material.
 9. The chip capacitor accordingto claim 1, wherein the first electrode film is divided into a pluralityof first electrode film portions and the plurality of fuses areconnected respectively to the plurality of the first electrode filmportions.
 10. The chip capacitor according to claim 9, wherein theplurality of first electrode film portions face the second electrodefilm over mutually different facing areas.
 11. The chip capacitoraccording to claim 10, wherein the facing areas of the plurality offirst electrode film portions are set to form a geometric progression.12. The chip capacitor according to claim 1, wherein the third electrodefilm is divided into a plurality of third electrode film portions andthe plurality of fuses are connected respectively to the plurality ofthe third electrode film portions.
 13. The chip capacitor according toclaim 12, wherein the plurality of third electrode film portions facethe second electrode film over mutually different facing areas.
 14. Thechip capacitor according to claim 13, wherein the facing areas of theplurality of third electrode film portions are set to form a geometricprogression.
 15. The chip capacitor according to claim 1, wherein theplurality of fuses are disposed with the positions thereof being shiftedso as not to overlap with each other in a plan view of looking down at aprincipal surface of the substrate perpendicularly.
 16. A method formanufacturing a chip capacitor comprising: a step of forming a pluralityof capacitor elements on a substrate having a front surface and a rearsurface, the substrate made of a silicon; a step of forming a firstexternal electrode disposed only on the front surface of the substrateand a second external electrode disposed only on the front surface ofthe substrate on the substrate; and a step of forming, on the substrate,a plurality of fuses that disconnectably connect each of the pluralityof capacitor elements to the first external electrode or the secondexternal electrode; and wherein the step of forming the plurality ofcapacitor elements includes: a step of forming a first electrode film onthe substrate; a step of forming a first capacitance film on the firstelectrode film; a step of forming a second electrode film on the firstcapacitance film so as to face the first electrode film; a step offorming a second capacitance film on the second electrode film; a stepof forming a third electrode film on the second capacitance film so asto face the second electrode film; a step of dividing at least one amongthe first electrode film, the second electrode film, and the thirdelectrode film into a plurality of electrode film portions; and a stepof forming an insulating film covering the front surface and a sidesurface of the substrate, the insulating film having a first opening anda second opening, wherein the first external electrode and the secondexternal electrode project upwardly from the first opening and thesecond opening, respectively, the insulating film is exposed on the sidesurface of the substrate and has an exposed portion which is not coveredwith the first external electrode and the second external electrode onthe side surface of the substrate, and the rear surface of the substrateis a polishing surface.
 17. The method for manufacturing a chipcapacitor according to claim 16, wherein the fuses are formed so as tobe connected respectively to the plurality of electrode film portions.18. The method for manufacturing a chip capacitor according to claim 16,wherein the plurality of electrode film portions are formed so as toface the electrode film, being faced across the first capacitance filmor the second capacitance film, over mutually different facing areas.19. The method for manufacturing a chip capacitor according to claim 18,wherein the facing areas of the plurality of electrode film portions areset to form a geometric progression.
 20. The method for manufacturing achip capacitor according to claim 16, wherein the plurality of fuses areformed with the positions thereof being shifted so as not to overlapwith each other in a plan view of looking down at a principal surface ofthe substrate perpendicularly.
 21. The method for manufacturing a chipcapacitor according to claim 16, wherein the fuses and the firstelectrode film, the second electrode film, or the third electrode filmare formed of films of the same conductive material.
 22. The method formanufacturing a chip capacitor according to claim 16, further comprisinga fuse cutting step of cutting at least one of the plurality of fuses.23. The method for manufacturing a chip capacitor according to claim 22,further comprising: a step of measuring a total capacitance value of theplurality of capacitor elements; and a step of selecting each fuse to becut based on the measured total capacitance value; and wherein eachselected fuse is cut in the fuse cutting step.
 24. The method formanufacturing a chip capacitor according to claim 22, further comprisinga step of forming, after cutting the fuse or fuses, a protective filmcovering the cut portion of each fuse.